What Causes the Exhaustion?

Exhaustion, might just want to go to sleep, and anxiety. What lik that, doyo, do you think causes the exhaustion? Im, just not knowing sometimes where to start, or how to sor to keep track of thingsi anto know where to start. It was really difficult last year, because there are times when i would just like not be able to teach. When i youno teaching, i just like religan, long on.