Your stressing and bad. I suggest changing teachers or whatever mentor is giving you that stress. start to take naps. sleep always revitalizes a metabolism.
Its the hormones kicking in, go to your doc if you are very concerned cos my sisters hormones caused her to develop alopaecia but she was in her late 30's at the time
You may also look into getting your thyroid tested. Believe it or not, this can be a side effect of thyroid problems. Hormones can be a culprit as well, but look for treatable medical condition too. Getting enough sleep at night can help, but also the weather can play a role. If you normally have a lot of hair and the weather suddenly got extreemly hot, some hair loss can be expected. Talk to your family doctor and see what they say. Stress is a horrible thing and it can effect your body in a lot of different ways. Also look at your diet and see if any recent changes in it could be the answer. Good luck and don't give up.
I'm not a Doctor but from my experience I think you might have caught a viral infection, something like seasonal flu.
did you have loose stool, water leaking from the nose, did you notice any difference with urination?
do you have any other symptoms at all?
Hair loss can be due to a immune response that is "shutting down" the follicles. the same thing can give you headache, bad memory, sudden need for sleep during the day, bad coordination.
I recommend to you that you talk about it with a Doctor and do at least Complete Blood Count and eventually other necessary blood tests.
If the problem was indeed viral / immune system it will heal spontaneously but it could take up to 6 months or even more.