Most teenagers are under constant stress. You don't state your age, and teenager is quite a large range of ages...it changes as you go through your teenage years. The things you write about are perfectly normal. But its a good idea to have a little talk with the school counsellor...I was a school principal for many years (retired now) and most counsellors are pretty good at what they do.
Please message me to let me know how you are.
You are not alone. See you doctor they will help