I want to pass along a practice / exercise that helps bring the nervous system back to balance. It is called Trauma and Tension Release Exercise (TRE). It has helped me quite a bit. I recommend it for anyone having problems with an oversensitive sympathetic (fight or flight) nervous system, PTSD-like symptoms, muscle tension, anxiety, relaxation problems, sleep problems, etc... like me. The concept is based in the science of how our bodies evolved to recover after a fight or flight response has been triggered.
This is not something to "cure" symptoms, but a great tool that can help our NS heal. I pair it with meditation to help keep a calm brain / nervous system.
I benefitted a lot from learning from a certified teacher rather than just watching random you tube videos about it. There are some therapists that are trained in it, so you can learn from them and get it covered by insurance. You can learn more and find a practitioner here: There are also books and videos.
Tension, Stress and Trauma Release : TRE(R)