Long COVID: Determining when to return to work

All jobs have their own unique demands. I'm a teacher and have been on FMLA for a month. My leave ends tomorrow, but I'm worried about going back and keeping up with the demands of a busy classroom, always being on, and the additional time needed for grading and planning while still dealing with dizziness, brain fog, fatigue, and headaches...not to mention appointments to help manage the symptoms. How did you determine when to go back to work, how did it go, and what recommendations do you have?