If she isn't interested in me why doesn't she leave me alone?

O.k. the first thing that stands out to me is that you have entered the friend zone. You had the chance to enter the romantic zone but for some reason she didn't want you there and now you will forever be known as her friend. Once you enter the friend zone, there is no going back to attempt and entrance into romantic zone. That door is closed in her mind. She may enjoy your company and respect your opinion but what she is doing is using you. Everytime a relationship with someone else doesn't work out she comes back to you because she knows you love her. Having your love and attention builds up her self esteem so she can regroup and try again. Unfortunately to get her self esteem back, she has to rob you of yours. Everytime she uses you for her benefit, you lose a little piece of yourself. Have you ever read "the giving tree"? The Giving Tree is a tale about a relationship between a young boy and a tree. The tree always provides the boy with what he wants: branches on which to swing, shade in which to sit, apples to eat, branches with which to build a home. As the boy grows older he requires more and more of the tree. The tree loves the boy very much and gives him anything he asks for. In the ultimate act of self-sacrifice, the tree lets the boy cut it down so the boy can build a boat in which he can sail. The boy leaves the tree, now a stump. Many years later, the boy, now an old man, returns and the tree says, "I have nothing left to give you." The boy replies, "I do not need much now, just a quiet place to sit and rest." The tree then says, "Well, an old tree stump is a good place for sitting and resting. Come boy, sit down and rest." The boy obliged and the tree was happy. This girl won't stop until you are nothing but a stump.