I have been doing good in high school since i got here, I am only in 10th grade, and i am already taking 6 AP classes, and i was flying through them very easily without studying. but then recently, my AP chemistry teacher is out on a maternity leave, and we got a substitute, and she is legit senile. she gave us a test on the first day she was here, and we never learned anything on it. I still managed a 74%. But the next weekend, she called my house to say that i failed the test, but i didn't. since then, I've been doing worse on everything, my life is out of whack, i got a 69 in trig. (i laughed at first, then cried, then i just laughed it off) and i got similar grades in my english and both my AP history (world and Euro) classes, this happened with the next tests in all my subjects too. I got a phone call home from all my teachers, i've never felt so stupid, i did so good in school before this, but now everything is falling apart, my social status is demolished, i can't go out because i'm grounded and have to study, so all my friends are forgetting about me, and my real chem teacher won't be back for another month.
What should I do?