She's my best friend and long story short, her behavior has cost her to lose every single one of her friends. She only has me and her family. I don't know why I haven't run away yet, I guess I do care about her but she makes me so, so angry and hurt, sometimes I wish I didn't care.

From her behavior in the past few years, I really think she's got some sort of cluster-B personality disorder, perhaps BPD. I don't know though. She once said that people who go for therapy aren't "strong", and that she'd never go for therapy. That was right after I told her that I was seeing a therapist. I don't know why I didn't defend myself at that time.

She makes use of me. The only reason she hasn't been kicked out of school is because I help her with her exams and assignments. She's never been grateful for it.

She's obsessed with men. Every man she dates, she falls in love and wants to marry them within a week. She can't handle a life without drama. She talks cr*p about my other best friends, I think she's jealous.

She used to emotionally abuse her ex. She'd threaten to cut/kill herself if he left. She screamed at him if he spoke of other women. I don't know what else happened behind closed doors, but from what I know, he wasn't even allowed to make eye-contact with other girls.

She's so so selfish, and shows off her stuff to me, knowing I can't have anything she does. She's VERY rich, her parents love her. She knows I'm not rich and my parents are abusive, she doesn't care.

For example (I don't want to give a real example, I don't wanna reveal who she really is), she'd complain about how she got a Mercedes instead of the Porshe she really wanted, indirectly wanting pity from me, while knowing that my family had to sell off our cars because we needed to pay for our rent.

I can't tell her anything because she's so scary. I can't cut her off because her parents know me very well, we're extremely close, it won't be easy. I don't know what to do, I'm so stressed out.