I'm afraid. I don't know who to tell... Who and how can I tell?!?

Well, I cut myself because I hate the way my dad treats me. He is trying to make memories of my deceased mother disappear. He took down all of the beautiful quilts she made. I try to tell him to stop and tell him how I feel and for a moment I actually believe he cares but he keeps on going. He remarried a month after my mother's 1 year death day and now all the pictures of my mom are replaced with her. He even said I'm his kid, not a person. I do and think everything he tells me too. He's said I have no freedom. For about two weeks now I've cut and thought about suicide. I've even planned it out before but stopped myself. I'm tired of of smiling because it hurts so much. I want to tell someone but I'm afraid, for some reason, they'll be mad at me. I don't want to tell my dad but maybe my sister. I'm mostly afraid because my dad married a physiologist that works with troubled teens. Please, how could I tell someone and who can I tell? help :(