Thank you to those who have responded. I guess now would be a good time to add points of clarification.

@Slamjammer Yes, I am able to sustain myself. I have a stable job and a savings account, I would be able to afford rent, loans, medical insurance, bills, etc. The only thing I would not have is a car to commute to work. I am currently borrowing my mom's car for that, but if I looked for an apartment near where I worked, public transportation would suffice. My mom may even choose to give her old car to me since she is looking to buy a new one.

@Nature1968 I know my parents have a point about my boyfriend and that they want the best for me. I definitely had my doubts about his financial ability, but I wanted to give him a chance to show/prove that to me. My parents refused to even allow me to give him that chance. I have met him in person, but that was after I helped him move to California. He had lost his job and I helped him with rent until he got employed again. He owes me money, but now that I have cut off all communication with him, I won't be getting it back. I don't intend to ask for it. That chapter of my life is now closed. I don't wish to revisit it.

Moving out would just be for my own sanity. I was not intending to move in with him when I moved out.

@Little Lulu Your last point about making arrangements before telling my parents is a great one. But since I am borrowing my mom's car, I need to tell my parents where I am going every time I use it. And in order for me to even make new living arrangements, I would need the car to view those apartments for rent. It's kind of a Catch-22.

Another thing I'd like advice on:

I wish to separate my bank accounts, credit cards, phone bills from my parents' accounts, but also do not know how to approach this subject as they believe I wish to further hide things from them. They can see all of my activity and have been monitoring it to further control me.