Unfortunately, "wimps" don't fight back. Ask anybody that's from the hood or that been in Maximum State Prison, they'll tell you the same thing.
But there is a great solution to this "bully" problem that you going through in school.
1) If you don't know how to fight, join free martial arts classes at your local community center such as YMCA, PAL, etc. to learn how to defend yourself ASAP. Meanwhile, wait until the bully that put his hands on you hangs out with his bully homies (inside the school) then go up to him and strongly tell him with authority "Yo, don't touch me again! The next time you or anybody else touch me again, I'll get the cops to lock your *** up for assault and anybody else that touches me too!" And as soon as he and his homies call you a "rat", tell him "I rather be a rat than a wimp!" then walk away. (Telling law enforcement on someone that's bullying you is not being a rat. As long as you press charges for your own safety, that's not snitching at all). It works.