Please Help me! I don't know what to do!?

Okay so my dad is friends with me on fb. He sent me a request and I accepted since it would be mean not to. So now, my mom and me are moving away, since he divorced my mom. Were moving in to the new house soon. He isn't living with us right now but he still comes back to check on things once in a while. He always posts dramatic stuff on my wall and all my other friends can see it. I try to delete it but I can't watch fb 24/7. He could post anything at any time! He hates my mom and says bad stuff about her on my wall. I'm afraid of him. Now when he comes over I try to get away so he posted on my wall how I run away and how bad I am. I can't delete him because I still see him once in a while and I don't want to make him mad. Please help me! My gf saw it and now she wants to break up with me too! Help me please.