Oh god. That's...terrible. To say the least. I really don't even know if terrible is the right word to describe it. I mean, my mother and I had our issues, but definitely nothing like that at all. Not even remotely close.
I'm sorry you had to go through all of that. No parent should treat their own child like that. It's not right. No one deserves to go through something like that. And quite honestly, while I like to believe that no one's really that horrible of a person, if your mother ever does come back, I'd probably punch her in the face if I saw her. And I'm generally not a violent person. At all.
It's okay. Sometimes you just need to unload and get things off your chest. I mostly just want to give you a hug, now. Or buy you a drink. Or both.