Idk how to think anymore

I’m 16 I lived on and off with my dad for a while . I have a step mom little brother. My dad is a principal at my high school. Sents 7 grade my dad would walk around in his fighting spandex under wear and it made me feel bad. I asked him to stop and he said he will if I did my chores. I’m a lot older now he still dose this he slaps my ass and I yell stop he dose it again he picks me up and pops my back when I say stop. Cuz everyone I can feel this stuff against me.my dad has walked in my room with out knocking me saying I’m changing when I hear him walk down the hallway he dose it anyways. My step mom think he joking around I don’t think my dad would ever do anything to me but I have had 2 dreams in the past 6 months of my dad rapping me as evarssing is that to say. I have a councilor who says she can’t do anything about it unless I think he would do something to be. I’m starting to hate my own skin when he around. I always try to stay out of the house but even when he talks to me I hate him with everything I have. Idk what to do or even how to deal with this.