Please help my mom

My mom has been in an abusive marriage for 26 years. My father used to beat me from 3 years old to 11 or 12 years old. He stopped at that time, but -almost in compensation- he became more verbally and psychologically abusive. He would not let me go to a psychologist because he was afraid he would get arrested. I had reported him before but he was able to manipulate CPS and they left. It’s been maybe 2 or 3 years since then, and I’m almost 18. He continues to manipulate what we can and can’t do with our lives, limiting what me, my sister, and my mother can do. He has financially bound us to him and because my mother was not able to finish college, she cannot provide for us or herself if she decides to divorce. She cannot have a job because she is getting old and she needs to take care of our dog as well. She is suffering, we are suffering. I attempted suicide last year as well as twice the year before that, but refused to have me treated because it was “thousands of dollars” which was not true as I had spoken with my psychiatrist about it. He has made every excuse to keep me stuck in this position, and even worse for my mother. Now, I can’t do anything because if he gets arrested, I cannot finance myself to go to college, and I am not eligible for a scholarship and students loans get worse and worse. I can’t get a job myself because of medical issues. I HATE THIS. Please please please help me. If you have any solutions please help me I just want my mom to be safe and happy without him