So sorry you're going through that. You don't deserve to be scared in the home that is supposed to be your nurturing refuge, leave alone by your own mother.
My mother was always raging and looking for something bad to say about everything and everyone. It's no fun to have a person like that as your mom, trust me, I know.
Just know that you're not alone, and that you have your life ahead of you. The right time to face life as an adult will come, and also the opportunities to start forging the life that you want for yourself. Hopefully you may not have to choose between her and your life.
I don't know the particulars of your story, but with my mom I had no choice but to learn to set boundaries with her. She wouldn't just quit. So little by little I started pointing to her how angry, bitter and argumentative she was all the time, and that "paradise" isn't exactly the word that came to mind when I saw her or hear her talking so badly about others. Notice that I didn't have to defend any of the shunned ones; I only pointed out her behavior, regardless of who she was ranting about.
That helped me some times, but sometimes she would just explode in anger and would start throwing things.
So yes, I wish I could say that things can get better, they never did with my mom, although later in her life she learned to behave better as she saw that as an adult I became quite happy and successful, while all she was still doing was ranting, arguing, yelling and preaching.