PCS can cause a variety of anxiety manifestations. OCD is a form of anxiety. Many have severe struggles. Have you sought help from a professional ?

I have struggled with looping thoughts. For me, it is just a mundane meaningless thought that plays over and over, sometimes into the next day. I was put on Paroxetine at max dose for 14 years. I eventually was able to replace the paroxetine (Paxil) with L-Tryptophan and 5-HTP. I have the same or better relief without the horrible side effects.

Are you following a vitamin and supplement regimen ? It is very helpful at helping the brain tolerate stress.