Last semester I took Honors Chemistry and my teacher accused me of cheating on my final exam, which I didn’t, so my parents and I talked to the dean and made me retake it. I retook it but got a worse score but ended with an A the first quarter and an A- the second quarter because of the bad retake score(my school goes by a quarterly schedule so the entire length of the class was 2 quarters long). I don’t know if my cheating letter got retracted from my file, but I should hope so because the teacher changed my 0 to a 70% on that test. The biggest problem is that when I was discussing the cheating accusation with my Honors Chem teacher, the AP chem teacher was also in the room(we were the only 3 people in there) so I would assume that she listened in on the convo. My honors chem teacher is very close friends with the AP chem teacher and have lunch together everyday, so I guess my main question is: What if my honors chem teacher gossips to the AP chem teacher about me cheating and the AP chem teacher ends up hating me next year when I take AP chem?(there is only 1 AP chem teacher in my entire school so I cannot switch to a different teacher).
@cy1999: You can’t prevent what the AP teacher may think of you, so next year, prove to him/her that you are a great, hardworking, and dedicated student. Take notes. Stay quiet in class (i.e. don’t goof off and interrupt). Participate/raise your hand and be an active listener. Turn in your homework on time. Do well on tests/exams. Show that you are not the person whom the gossip says you are.
Life is unfair and we can’t really do much about some things 
I second what @thelittleswimmer said, just use it as motivation. Just don’t hold a grudge or change your attitude towards the class/teacher, as this will only hurt you.