I don’t know what to do anymore

I honestly don’t know what to do anymore. Let me explain my story. I’m a 17 year old girl, I turn 18 in 9 days. I stay with my grandparents because I had to move out of my moms. My mother was/is not a great mother. She is stubborn, cold and only cares about her boyfriend. I moved out because she began to get physical with me and I can understand when you give your child a whopping but when you physically try to fight your kid that’s a different thing and that’s what she did. She did it on more than one occasion and when she did it the third time I decided I had enough and left. I went to stay with my grandparents who I thought would be supportive of me but they weren’t/aren’t. I’ve been living with them and it’s been a year now and it’s the same old thing and to be honest it’s not really my grandma it’s my grandfather. He’s constantly throwing up in my face about how if he didn’t let me live with them I wouldn’t have anything, they give me too much freedom, I don’t pay enough bills, and what hurts the most is he saids I’m bothering them. It makes tears come every time he saids that. I’m only human and he’s always trying to find something to get mad at me about. I don’t do anything but go to work school and sometimes I’ll hang out with my boyfriend and it’s not even all the time I only hang out with him every other Saturday. He’s constantly saying I don’t pay bills. I literally make minimum wage at Subway it’s not like I’m getting 700$ checks . I barely make it to 150 sometimes. My subway doesn’t even really give me hours. But back to the point. I feel like I have no family. I feel like I’m just a nuisance to them and I want to leave and not come back. My grandmother never has anything to say. Which makes me angry she just sits there like a scared puppy. Before I started typing this I had thoughts of cutting myself. It used to be my coping method and I might resort back. I’m grateful for my life but I just have so much weight on my shoulders. Every which way I look I feel like I’m doing something wrong.