Hi Nick33 and welcome. I just wanted to say hi but can't write now, I'm just off to bed.
It does get better. Therapy with someone who specializes in trauma can make all the difference. I have been delighted with Somatic Experience therapy. Got to release the trauma at a body level as well as emotionally, etc. - at least for me that helps significantly.
My husband was a fire fighter. Bless you for the work you've done. I'm not sure what your what ifs and maybes are.
All I can deal with is today. I can take action to undermine the traumas that occurred but the past is one thing that cannot be literally revised. I understand the obsessive thoughts. It's like the brain keeps trying to fix what we feel shouldn't have happened. That's a fast track to insanity for me though.
I pretty much try to accept what I can't change and focus my energy on what I can change. Sometimes that's easier said the done!
Anyway, glad you're here.