Why does my life suck?

I can never focus in school and my grades have gone from 95s to 70s and I hate all my teachers. I had great teachers last year. Now all of them are boring and give boatloads of homework and expect that it's going to be turned in the very next day. I've stayed up till 11 doing homework. I hate my school and all I think about all day is going home and dancing. I do dance and I'm really good at it. It's my passion and I want to become professional someday but that's not going to happen if I don't get my life sorted out. My school is terrible. I have friends but I also have enemies and I'm sick of all the boring classes. I hate school and sometimes I just feel like breaking down and crying but I don't. I get made fun of by some people but that's not a huge problem because it doesn't matter to me. I'm just feeling more sad about things and I just want to be at dance all day and I'm tired of my school and I hate it and when I'm there I feel like crying. What do I do?