I can't exactly relate to the trauma but I can relate to being unable to sleep.

Overactive thoughts are what mainly keep me awake, and apps like Calm or Headspace are free to start and make it very approachable. Difficult at first, you you'll get better with practice, and once you learn the basics you can do it on your own without paying a subscription.

If your body holds onto tension it can be difficult to relax and get comfortable. Perhaps do some stretches or use a foam roller to relax your back (personally I use a Chirp wheel, they're fantastic!).

Also if your body simply isn't tired it can be nearly impossible to sleep. Doing some pushups or squats enough to get your blood pumping helps, though I don't recommend doing this immediately before getting in bed as you'll likely feel more awake for a little bit after.

I hope this helps!