Comment by michaelkeenan

I know you've probably already tried lots of things, and you're also inundated with ideas from others, but:

Here's a psychiatrist's guide to solving insomnia: https://lorienpsych.com/2021/01/02/insomnia/

And here's a psychiatrist's guide to solving nightmares: https://www.astralcodexten.com/p/peer-review-nightmares

Prazosin is the standard drug for PTSD-related nightmares: https://en.wikipedia.org/wiki/Prazosin