I struggle with similar symptoms regularly. For me the culprit is boring old anxiety. I know how to relax. I know I am not in danger. Anxious brain gonna do anxious brain stuff. Not saying this is your solution, but it sounds very close to my experience. Just like they say drowning doest look like it does in the movies, anxiety can present in many ways. Therapy is a really good thing. If you feel weird about that, I’d say (forgive the woo woo) just go for a walk every day for a week. Sounds like your brain needs a break. Love to you boss. Times tuff.