I think that "stop hurting yourself" means that when you get a bad grade you are hurting yourself. I think Mr. Hsu put it up to tell us that if we do bad in school, it only hurts our selves. I havent seen anybody cutting their wrist, but i know a person that is emo, and they are always denying it. It affected me because i dont really like emo people because they are all P**SIES (hope i dont get in trouble for using that) trying to die, and they are afraid of life, and it also affects people around them like their parents.