Molly, remember that your actions should be thought through before you act on them. Maybe instead of running out, you can come to an agreement, through your mother if you have to, that you are a tenant there and you have personal space and personal respect. Just running with no real plan is a bad plan. Get out--but only if you have something planned, somewhere to go, someone to share a room with and a plan for the future.

Make sure you breathe and relax and think when confronting him. Let the emotional side of you take a back seat to the intelligent part of you and show him you are mature and not some little kid he can kick around.