Tired brain fuzz splat fall?

I've been having trouble sleeping for several weeks. It's a familiar pattern, but not one I have ever worked out, comprehensively, how to break. There's a range of things that sometimes work, but none have in this case.

I sleep less and less, at weirder and weirder times. I lie awake in the dark for hours on end. I get tireder and tireder and it leads to worse and worse dreams, and bad half waking nightmares. I wake up randomly, at random times, unrelated to how long I've been asleep. Then I sleep nine or ten hours, regardless of whether I want to wake up or not, and related things like alarms and light levels. Rinse, repeat.
This culminates, usually with terribly inconvenient timing (as now), in the ultimately annoying place where I don't sleep for over 24 hours and then have to try and choose between sleeping the rest of the day away and risk going totally nocturnal, or stay awake until early evening, sleep for a while and er...risk going totally nocturnal.

Also, it feels a lot like drugs. Who needs opiates? Sleep deprivation! Seriously.

And I hate it. I need my brain, right now. I have things I need to be doing with it, and now is not the time for woggly pictures of my brain on insufficient sleep. Now is a time for freshly pressed brain, clean and tidy and nicely oiled.

But I don't have one of those. I have instead the kind of brain that comes up with strange brain metaphors.

Sleep will be soon, I think. I don't know I have a choice about it, actually. And maybe that's better. I will sleep now, and deal with the consequences later.
When later is the only question: Will I sleep two hours, five hours or eleven hours? Who knows?

I have to work out a fix for this, and soon, even if it's only a temporary one.