I really need to open up about this:

There is a girl I really hate. All she wants is to make me lonely. And how do I know it? We were friends when we were 8. She was my best friend and told me not to have other friends and I thought I needed only her so I cut my ties to all other people. And then she just left me. In middle school I forgave her, tho she never apologized, and we were friends again. I knew she used me, she always ate my food and drank my drinks and carpooled with us and all I ever got from her was... well, she told me that all other girls in the group were bullying her so of course I stood up for my friend and lost my other friends. Then one of them showed me messages she had sent them: and yes, SHE WAS THE ONE WHO WAS BULLYING. And not just them, she called me all kinds of names, MADE A LIST OF ALL THINGS SHE HATES ABOUT ME, said I never did a thing for her. When we told her that if she hates as that much why won't she make new friends, she said that she doesn't want to know new people.

Untill the high school started. I made two new friends and that one a$$ always came to us, pretending she never said those things behind my back. One of my old friends is still friends with me and her and she (my friend) confessed to me that only reason she is with her (the backstabber) is that otherwise she'd be alone. Somehow my dear backstabber tries to become friends with every single person I talk with and tries to get them against me. 

And now I am organizing a surprise party to my friend. The backstabber must be invited, because otherwise "she'll be sad" (not my opinion, the friend who pities her said that). Seriously I hate that girl all she wants is to get, she never gives a thing and when she doesn't need a thing from you anymore, she dumpes you. She's good at manipulating and getting people behind her and now I fear I'm going to lose all my friends because of her. 

She has has never apologized me or anyone else she hurt.