Evolutionarily, insomnia makes sense in the context of a tribe, where it's useful to have people up and about, watching for danger. But in the modern day with synchronized workplaces, we've seemingly decided that not waking up early verges on a moral failing. "Early to bed, early to rise, makes a man healthy, wealthy and wise," is just the beginning. Showing up late to work is looked down upon, but staying at work late is underappreciated, in my experience. Being on the east coast is a surprising benefit when working with West Coast clients because it creates the impression that I'm getting more done simply because of time zones. There's something deeply ingrained in US culture going on here that I'm not sure I understand the full extent of.
What works for me is reading low stakes fiction. Smutty fairy fantasy novels and things like that. They require zero real thought, and are relaxing enough to not stress my mind. Combine that with a massive bean bag chair full of latex rounds instead of regular stuffing.
Also, I've noticed a difference at my employer from your experience. The people who stay late (but also come in late) are promoted, whereas the early risers like myself are chastised for leaving early.
I'm still tired seasonally when the insomnia really flares up, but I'm not the walking dead anymore. And no psychotic breaks for a decade.
I had one boss who got fed up with the early risers like me apparently bunking off early, so he instituted signing in and out... and discovered that we worked longer hours than the late arrivals, in some cases a lot longer. The experiment was discontinued after a few weeks.
It's interesting that today this is very quickly framed as pathological, but in a lot of cultures biphasic sleep actually used to be common. A lot of preindustrial English language literature for example makes explicit references to "two sleeps". Many people used to sleep from around 9-11 pm, then engaged in various activities for one or two hours and continued to sleep. It kind of blew my mind when I heard about it the first time because of how completely this seems to have vanished, not just the practice itself but also discussion about it.
I think for people stressing a lot about sleep it's probably worth taking into account just how artificial the whole factory-job era on the clock sleep schedule is.
https://www.bbc.com/future/article/20220107-the-lost-medieva...
If the prospects seem good, trying getting back to sleep for 10 minutes. If that doesn't work, there's always work to do - so get up, start a load of laundry, and catch up on some things while it runs. Consider making a hole in your schedule, so you could get a couple hours sleep after the laundry's done, or an afternoon nap - but it that wouldn't work - well, such is life.
(Yes, I'm an old geezer. And back in the day, there were quite a few farms in my family.)