I don’t know what to do

I'm sorry this has happened to you, maintaining friendships is hard, especially when the other person knows a lot about you and you feel they may be becoming unhealthy for you. :( I don't think you should just sit by and take it, but don't make the break up of your friendship become a supernova. Simply cut it under the pretenses that as she WAS your friend, you TRUST her to understand that you want to meet new people. My view is that to get all bases cleared and for things to be out of 'her' control and for you to feel safe and happy. I would tell your parents of this relationship you had so SHE cannot use it against you. If your parents are understanding, hopefully they'll see your courage and honesty to tell them 'personally' of your decisions. Sit them down, make a list for yourself if you have to, and tell them them why you felt an attraction for that person, and in the end, make sure they understand that you told them the story because your once 'best friend' is giving you trouble and you weren't going to let HER tell your parents instead of yourself to their faces. Honesty is the best policy when it comes to relationships. I wish you luck, dude. :>