What do i do about this guy?

ok so this guy at my school i'll call him tom ,a while ago he started sayin stuff to me like pikin on me but i thought it was just like playful teasing until one day he just turned nasty and the names got worse, on this social site lets say fb (not really facebook) he was calling me stuff like b**ch, i had a cold so the next day i wasnt in school and he wrote me a message saying 'hey i guess you where too scared to come to school? u f**in b***ard ha! ' , and then when i went to school he acted like nothing happened and he was just been anoying in a playful way, so everything was kind of ok until today at school i was walking past him and he stood right in front of me and called me a f**in b**ch and then punched my arm like 5 times so i pushed him away and walked off like ouuch!, my friend was there but she couldnt do anything cos he picks on her 2 but not as bad as me. and then at the end of school when he walked past me he went 'oooft annie' so i said 'urghhh tom' . so should i report him to my teacher because i dont want it to get worse but i dont know if its bad enough to report i mean i dont have bruises from when he punched me but it hurt. and please dont say that he likes me cos he does not!! he hates me and i hate him with a burning pion! ive tried been nice but he jusut doesnt take it! what do i do about it! :(