I want to physically hurt myself?

I don't know what to do, when I'm around my mom, I always want to kill myself and makes me want to self harm. Since I was born till when I was 7, my dad used to beat her and make her drink and do drugs, and my half sister. Same mom not same dad. Would have to hold me back as we sat there and had to watch it. At 7, we moved away to Texas and lived with my stepdad, who is just like my dad except the drugs and drinking and abuse. At 10, I developed acne. And around 12, it got worse than normal and I was diagnosed with cystic acne, look it up on google pictures. My face and back and chest are covered in it, they look like blisters. My dad and his acne has caused me hurt mentally. I am over sensitive and over emotional, I self harm when times get too bad. My mom knows, well knew, she thinks I stopped but actually I just cut on my thigh now and she doesn't know. Now onto my mom, she blames everything on me. When I'm talking she interrupts me, she nags about everything I do and if I'm talking to her she accuses me of yelling and nags about that, she says I'm just like my dad and that pisses me off more. I tell her it does but she still does it. My mom is overprotective and tells me that she's going to check my iPad hard drive and that gets my anxiety high. You would have to know her about all the **** she does to me.
Added (1). Oh and I was sexually assaulted at 5 or 6 and she knows.

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