What should I Do to fix this?

That's a difficult situation... Try not to let your mom's comments get to you, as she's just projecting her stress and anger with her husband off on you. It's probably best if you try to spend as little time around your house as possible, as it seems to be a very toxic environment for you to be living in. If I were you, I would try to find a counselor (school or otherwise) or someone to talk to. I understand that this must be incredibly stressful for you, but please don't cut yourself! There are healthier ways to deal with the stress. Also, I know that it must be very hard for you right now, but remember that you only have 2 years of high school left before you graduate and can get out of there. I'm sorry that you're going through such a hard time, God bless!