How to tell my mom

KahNog.
I'm 21 years old and I'm planning on moving out with my boyfriend. The only problem is that everybody at my house hates him. He's a hard person to deal with, but I love him and we have been together for 2 years now. (When I was 18 I moved out with my ex but we were too immature and it ended up not working out and I had to come back to mommys house) i just need my own space. I live and work together my mom, and I feel like I don't have any freedom. She pays me around $350 a week and expects me to help her with the house bills and wants me to buy a car but I don't earn enough money. My boyfriend used to be a lazy ass but he has Shown me that he wants to be a responsible guy and is working a lot to make things happen for us. I don't want my mom to be mad at me for leaving the house again, but I can't just stay here and let her throw in my face that I'm nobody . What should I do?