In my case it seems it was more due to cardiovascular problems than to PTSD or 'brain self-harm' if I may say so. But anyway, I do try to have deep slowing moment[1], aiming at stable relaxation. But I'm never sure what to expect from meditation. Give me your favorite books.

[1] a side effect of fubared cardiovascular system is that I had to monitor my breathing and heart a lot so I would naturally have sessions of calm slow breathing exercises.