How do you break up with someone you live with who is dependent and possessive?

I am bisexual and I am with a girl right now. We have been together for over 3 years. The past year has not been easy as we have been fighting a lot, over the littlest things. Ever since we got together, I have drifted away from my family, my faith, and even my own individuality. I do not want to break up to party or anything like that, I just want some ME time. Time for myself to focus on my studies, my job, and be able to spend time with my family whenever I want to. She is very dependent and clingy. I am the total opposite. I have given her hints that I am unhappy but she is still trying to work it out. I feel so bad but I can't help feeling this way. I feel like I need time on my own to grow as a person and to better myself. How do I make her understand that?How do you break up with someone you live with who is dependent and possessive?
Be honest with her and tell her that although you love her, you know you're not right for each other and that long term this will never last. Assure her you are not interested in anyone else, but that you have to leave before your love turns to hate. The fighting is wearing on you and your feelings have changed. Give her a time frame as to when you'll be moving out so that she can make arrangements too. You both need to be with someone who loves, respects and brings out the best in you.