How can i feel indifferent to all the bull in my school?

Ok, i go to this high school where there's a lot of bullies. I know how to deal with this. Mind ur own business and they dont bother you right? but theres always those days where they purposely bump into u (ur walking n theres a whole load of space to p u...and they find a way to bump still -,-) then trash talk about it 2 u. i cant fight n i cant trash talk (stutter a lot). Usually i stay silent n let it go (smart thing to do), but my eyes get a bit teary....deep down, those things still hurt. How can i feel indifferent to it to the point where no tears would b forming after hearing all those insults?