What is wrong with him and what should I do?!?!?

OK, this is just a fair warning: THIS IS GOING TO SOUND CRAZY. I have an English teacher at school and for some weird reason he keeps staring and smiling at me all the freaking time. And what else is weird is that I've had an A + all year in his class even when I did poorly on a test. So the other day I walk into class he stared and smiled at me more intently like he wanted me or something like that. And after class he told me to stay and help. When everyone left the classroom, he said something about me being one of his favorite students and he started touching my *** and he was trying to kiss me and trying to ~!@#$$^(*$&. But I wouldn't let him and I pushed him away and fortunately got free and ran out of the room. I'm really petrified and I'm afraid to tell my family, friends and people like the principal and the school counselor but I want to tell them what he's doing because I would be stupid to keep a secret like that. So what should I tell them and who should I tell first. PLEASE HELP. I feel VIOLATED :( :( And then teacher is like maybe 20 some years old thought I would add that. HELP!