Shutdown

Hi I have recently had three episodes of work for a few weeks because I think my body was shutting down with information processing and keeping up. I used to get migraines which ere a shorter period off work but know I’m in a better job that is very supportive but I seem to be still unable to stop getting exhausted weak fatigue slured  speech and impending doom . Sleep helps and being on my own . Does anyone else have this problem? How do you stop a shut down coming ? What can you do in stay in work? Alice