I moved back home to my parents house because they left and wanted me to look after it. My sister is also living there, but she has been physically and emotionally abusive to me my entire childhood and early adulthood, and she has the balls to be abusive to my parents too. I have plenty of evidence for this.

However my parents still have a preference for my sister. I'm seen as someone that's far too kind to people, and I am often taken advantage of (I am trying to change this). When I was 14, she snuck up on me and hit me in the back of my head with a textbook. I was diagnosed with a concussion, but my parents didn't care. Even when they witnessed it, they wouldn't even try to stop it.

I started noticing a theme; my sister can do the absolute most horrific thing to someone, but my parents will protect her and even blame the victim. I was often yelled at for getting hit by her saying that I deserved it. My old therapist suspected that she had narcissistic personality disorder.

A few days ago, she hit me for the first time in a long time. I hadn't done anything, she was just mad at her boyfriend and I happened to be there when she got mad. She grabbed me and kept hitting me on the back of my head. The only thing I did was try to run away. I eventually got away and came back several hours later. There was a security camera which took a snapshot of what happened, which corroborates my experience.

Since I'm a guy, my testimony is worthless. My parents and society will believe and protect my sister. Even with that snapshot as evidence, people will refuse to believe that my sister physically assaulted me. I still have a bump on the back of my head where she restrained and hit me.

I didn't bother telling my parents because I know that they'll defend her. I'm still considering filing a police report, but I don't know if I should because they'll take her side too.

I'm making arrangements to move out. But in the meantime, is there anything that can be done so that I'm protected?