My stepdad keeps touching me...? Runaway...?

Tell a teacher at school to get you help. He needs to be punished for what he is doing. Tell your mom. If she doesn't believe you then you can still have your teacher or some other adult you trust help you out of this situation. Don't let him run you out of your own home. He is the one that needs to go. Plus, what would you do if you ran away? How would you support yourself? Where would you live? You need to think about these things.