You are feeling very sleepy...

I'm tired. And I'm tired of being tired. It's just so tiring.

It's the old radiation fatigue. It's not going away, and it's becoming a nuisance.

It seems to have been hanging around me like a lead cloud for weeks, like I'm swimming in jelly while wearing an Aran sweater. And the haircut isn't making me any more streamlined.

It will go away, of course. Probably. But I don't know when, and the unpredictability is the worst bit. I can't plan my day.

While I was still being zapped on a regular basis, I knew what to expect. I'd get up feeling fine, start to flag a bit by lunchtime, have a nap and a snack, feel better, start to flag a bit again in the afternoon, then have another nap to restore me for the trip to hospital to top up on sub-atomic weariness for the next day. All well and good; I could work round it.

This, though, is just awkward. Most days I still get up quite energised, but where things go from there is anyone's guess. Most days I have three or four hours clear before it starts to creep up, but on others I'm feeling it before I've even left the house.

It starts in the muscles of the arm, a little like the onset of flu but without the actual ache, and moves quickly into a slight dizziness, a sense of dissociation from my surroundings that means I'm no longer quite able to focus, sometimes accompanied by lethargy that feels like depression. It's a little like being drunk – and if you don't see what's so bad about that, to paraphrase Douglas Adams: ask a glass of water.

None of this is particularly debilitating, and I can push through it quite easily. But doing so comes with the knowledge that there's a debt to be paid later.

Sometimes I can stave off repayment. Eating helps: I think low-carb, high-protein stuff like nuts are most effective, sugary things seem to produce a false high. Coffee may or may not help: that may just be an existing addiction. Drinking lots of water certainly helps.

But, like running up a credit card, it doesn't really go away. Eventually, I need to tackle the bill. And all that really works is sleep. It won't really be cleared until I do that.

Which isn't so bad. Sometimes I need a couple of hours, but mostly half an hour will drag me back to normal; sometimes ten minutes is enough. Problem is, I started back at work last week, and while it's good to be back on project and with a daily purpose again, I can no longer merely retire to my couch. I'm in a place of business, among colleagues, and nodding off against the ergonomically-designed desks isn't a good look in a modern working environment.

So I push through it and rack up the debt, and eventually it hits. Usually in the middle of something I'm trying to concentrate on, occasionally mid-sentence. It's like the cold shock of a bucket of water, but with reverse effect, slamming me into torpor. And at that point I have to go home.

Fortunately, my employer is flexible enough to allow me to do that. I just have to get up, go, and try not to fall asleep standing in the bus queue. But it would be nice to know when it was going to happen. So I could guarantee to be at meetings, for instance.

Take last week. Monday, my first day back for three months, wasn't too bad. I got what I needed to do done, and made it to mid-afternoon before bailing out. Tuesday I was in hospital for most of the day, so no problem – they're completely happy with patients falling asleep, except when they're shoving sharp things into you, which they like you to experience and feed back on. Wednesday, though, was awful: I barely made it past lunchtime, and though I pushed on as far as I could, I went home with the determination that the next day I would be in only for long enough to explain that I'd come back too early, I wasn't ready yet, and would have to get my sick line extended.

On Thursday, of course, I felt fine. Great, in fact; made it through to after 4.30pm before feeling that I should probably call it a day. And that's been the thing since: some days are tremendous – today was fine, thanks, did my first full shift since returning in fact – but others are bloody awful. Yesterday I felt so bad I was in for only a couple of hours.

Some kind of pattern would be nice, but all anyone can really tell me is that this is all perfectly normal.

I'd been told to expect the fatigue, of course. Two weeks, three weeks, six to 12 weeks of it, apparently. It could kick in during treatment, I was told, or weeks later. No one seemed very sure, but I was certainly warned. It varies from person to person, it seems. No-one knows how it will take each individual. Fine. I just wasn't expecting inconsistency with it.

I was definitely feeling it in the last weeks of my treatment, for instance, and felt increasingly better each week as it stopped. You'd expect that to continue, and it appeared to: when I got to Gran Canaria, I felt not at all bad, and I returned refreshed, relaxed and ready for anything.

Except, that is, for the decline which kicked in within about three days of returning to Scottish soil, and really hit just in time for getting back to work. My timing, as always, is impeccable.

Still, things are otherwise going pretty well. I started adjuvant chemo this morning, which is double the dose I was on previously, with no apparent side-effects. My platelet count is apparently normal, so I can continue to drip-feed the Beatson's pet vampire without running out, and my white cells are doing whatever it is they're supposed to. Plus, today was simply beautiful – a perfect, fresh spring morning, pale blue and crisp. And that made me feel fantastic.

Little things, it seems, do mean a lot.

I'm going to bed now.

A piece of mind, for your peace of mind

And… we're back.

The week on Gran Canaria was excellent, thanks for asking; exactly what I needed. I've returned well fed and watered, thoroughly relaxed, and with less sunburn than I left with, which may be some kind of record.

It was a fairly limited holiday insofar as I didn't stray too far from the hotel. We had a daily routine of getting up around 9am, heading out for some brekkie and a wander around the town, popping back to the hotel around 11.30am for a wee nap on the sunloungers when my post-radiation fatigue kicked in, taking a trip out for afternoon lunch and drinkies, popping back for a late-afternoon nap and then heading out for the main eating event in the evening. A gruelling regime, but someone had to do it.

As the week went on, the periods I needed to sleep seemed to reduce and the fun bits in between to extend. Saturday – when we had to check out of the hotel at mid-day, right at the height of my daily exhaustion with a huge gap to fill before the flight at 8pm with no recourse to nap facilities – was hard, and I felt it quite badly. But there were no whistlers in the airport and I managed to sleep for most of the flight, so I got through it. And now I'm back, I definitely feel better for the experience. Not completely without daytime tiredness – it's 12.45pm on Monday as I write this, and I don't think I'm going to get to the end of the piece awake – but feeling much, much more relaxed and ready for whatever comes next. Taking a holiday has undoubtedly added a massive amount to my general well-being.

Which makes it all the more galling that I very nearly didn't go at all. The reason? Travel insurance.

It's not something I've bothered much about before. I travel light and don't take much on holiday I'm not prepared to lose. Clothes are just clothes, and those who have met me will know I'm not an expensive dresser. I do tend to carry a small media centre's worth of electronic kit with me at all times, but it's surprising what your standard household insurance already covers (this is a Top Tip, incidentally – always check that one out). Health cover is the only thing that has ever really concerned me, and as long as I'm staying within the EU I tend to rely on the EHIC (the old E111), that comforting little blue card which gets you the same cover as a national of any EU country you happen to be in. It doesn't cover repatriation and may require the odd up-front payment, but whether you find that acceptable boils down to your attitude to risk, and I think it's more than enough.

Last summer, before my impromptu jerky dance and all the horror that ensued, I went on a short Aegean cruise, and I did take out travel insurance for that, just in case of exotic drinking incidents while in Turkey. It was a simple process: I went onto one of the big online aggregators, shoved in my details, and was drowned in options to cover me for the week for about a fiver. Sorted.

So this time, I did the same. Although the Canaries aren't in the EU – they're largely autonomous of Spain, I suppose like the Channel Islands here – the EHIC still covers you, but I thought that with my current condition the extra security might be nice, just supposing I suddenly felt worse and needed my steroid prescription increased, for instance, or in the very unlikely event I had another seizure and hit something during the ensuing horizontal flamenco. So I went onto the same aggregator, this time clicking the 'existing condition' button, and declared my glioblastoma. And the results were quite different: instead of the hundreds of options presented to my lump-free former self, I was given one – for a sum which was effectively going to double to cost of the holiday, just slightly less than the price of return flights and seven nights in a good hotel for both me and Clare, just to cover me.

At that point I almost gave up. The holiday booking was a last-minute affair, and was only going to get dearer as the date approached, even if the flights didn't disappear entirely, so I didn't have much time to shop around by more traditional means. Looked like I was going to have to just chance it, or forego the holiday.

I gave it a further 24 hours, during which time I spoke to some medical professionals – no names, no pack-drill, but some were pretty senior. I wanted to know specifically what kind of emergency medical treatment I would be likely to need, given my condition. And the answer was that, while no-one would advise me to travel without insurance, well… none. There was more chance of me needing it to cover for being hit by a bus. Which, if you have experienced Spanish traffic, is a risk of sorts, but one I take every time I go there. I booked up that evening.

So, Mr Insurance Company, what's your excuse? Insurance is, as I understand it, all about risk: a kind of gamble in which I pay a small amount of money in exchange for you covering a much higher cost which you have calculated is unlikely enough to not happen to make it worth your while taking the bet. Most of the time you get to trouser the cash, but I get peace of mind in return. That's reasonable enough.

What you're actually doing, though, is merely predatory: you're simply accepting no risk at all, and taking the cash anyway. Either you just ignore the business, happier to take the thousands and thousands of guaranteed fivers from healthy travellers, or you parasitically suck on the fears of sick people, taking very large sums you know simply don't reflect the risk involved.

I wonder how many people with chronic conditions simply remain at home, crouching in the cold instead of grabbing a spot of much-needed rest and relaxation, because they're too frightened to take a chance they don't realise might be very small, and unable to pay these charges.

I saw only one quote. Well, actually, I saw two since I also got one from the same company for travel insurance in the UK: that sent me through the ceiling, since even it was in the low hundreds for cover in territory in which the NHS will provide everything for free. I know that doesn't form even the basis of an investigation - this is a blog, so I'm allowed to rant based on personal experience - but there's a story here. I may come back to it.

In the meantime, Mr Insurer, if you can sleep at night, do try to lose your grip on the rafters and drop on your head.