I mostly solved my insomnia — which was also largely due to that racing, bADDass brain of mine — some years before my diagnosis. Here’s what worked for me (last one is my original discovery, the others I got searching for advice about insomnia online).
Melatonin. I won’t tell you what dosage to use or when; do your homework first.
No light. I use thick blackout curtains, and I’ve put electrical tape over every LED in my room. When I sleep somewhere else, or a partner needs some amount of light while I’m sleeping, I use and eye mask.
White noise. This is critical to keep me from trying to parse what every sound I hear means, or from hearing that someone else in the house is having a fun sounding conversation.
This one I stumbled on: audio books or podcasts that I know and love. It has to be one I know well enough that I can drift off without losing track of what’s happening; I’m not interested in finding out what happens next, but I can’t be bored by it either. Sometimes I have to make sure to re-listen to a book, and then in a couple of months I can work it into my rotation.