My mother was the same way with me. She told me I was worthless, that I would never amount to anything and that she wished she had aborted me. I attempted suicide 3 times between the ages of 13 and 15. So I know how you feel.
What your mother is doing is not right, and it's not your fault.
You are a smart, capable and worthy person and she is wrong to say these things.
Your mother needs to go to counselling to learn how to cope with her anger. Right now, the best thing you could do is find an adult you trust and tell them what's happening. You need an aunt or uncle who can help you, and maybe even let you stay with them for awhile. If she won't go to counselling, you need to talk to an adult in social service who can help you get some additional help. You are going to need to talk to a counsellor, because what she's doing to you is hurting more than just your feelings. I could have been dead right now. I don't want you to end up the same way.
Good luck