I had a similar issue a few years ago. After a lot of running around taking to doctors and getting tested, a psychiatrist nailed it down as being chronic anxie

I had a similar issue a few years ago. After a lot of running around taking to doctors and getting tested, a psychiatrist nailed it down as being chronic anxiety leading to executive function shutdown, medicated me for a few weeks, and sent me to therapy. This helped a lot. I also improved my life in general and it's slowly coming back, though I still need to be on vacation for a few weeks to be whole. Tl;Dr: anxiety and burnout. Fix your life and get therapy. You can't run from stress, but you can reframe it productively and that turns it from bad stress to good stress. Might need a change of manager.