I also am suffering from something similar. I have the working theory it's from extreme burnout but do not know for sure. I would tremendously appreciate if you shared what you found to help?
FWIW, I think it’s unlikely my problem was burnout - I had a number of viral-characteristic physiological symptoms such as digestive problems, coughing, and heart palpitations, and I would be surprised if they had a purely neurochemical cause - but in either case hopefully some of these behaviors could help.