Has your dad ever spoken to your mom about her behavior; if he's aware of it?

First, I want to point out that nothing you described here can/should ever be described as weakness. Crying, cutting...neither of those are weaknesses, they're coping mechanisms. It's really no wonder why you have to utilize them, dealing with a "mom" like that. My dad would call me a liar and things when I'd confront him about what he did, after some time I just felt like I was crazy and imagining everything was worse than what it was; I'm still dealing with this, though I'm coming out of it slowly. Don't let that happen here. Your mom, she sounds like she's not currently fit to be a parent. Is there any way you could talk to a school counselor about this, maybe? Just so you can speak to some adult about these things. I had to do this when I was still dealing with my dad because I'd get it real bad if I spoke to anyone else.