Does masturb4ting make you do this?

Im 15 and i've gotten into the (bad) habit of . i've been doing it for maybe a couple of years now but I'm kind of concerned. I've slowed it down alot, but now I get exited at the dumbest things and at the worst times. In school, standing in line, in church, all i need is something to flash, I don't even have to dwell on it, just flash across my mind and bang pow, there I go. Its kind of annoying and embarring. And on top of all that, i'm fairly large so EVERYONE CAN SEE!!!! how can I stop this?