Step Mom Attacked Me

I don't get along with my step mom at all. She constantly belittles me and makes me feel awful about myself. She wanted my dad to kick me out on my 18 birthday, but he refused and said I can stay as long I want. I work and I'm saving for an apartment. I'm taking classes at the community College. She has called me a bitch, threatened me, bullied me into an eating disorder.... Said my mom killed herself because of me... last night things got real bad. She had been drinking and I was laying on my bed. She came in saying she was missing money and asked if I took it. I said no. She called me a liar and a sneak and that all I do is use them. I told her to get the hell out of my room and she hits me in face and attacks me! She is hitting me in the face and grabs me by my hair. I feel her nails in my scalp me starts banging my head on my bed frame. She then let's go and I see me dad. He hit her really hard in the eye with his elbow and asked if I was okay, but I just got up and ran out the house. I didn't really have anywhere to go so I stayed gone for a few hours and then went home. She was gone and my dad hugged me saying he was worried and he's sorry and that he kicked her out. My step mom has been calling my dad all day and he's ignoring her. I'm just so scared he's gonna bring her back....