So, /r/relationships actually told me this person was ABUSIVE (classic) and I think that's a gigantic stretch but I certainly do keep her at arm's length these days.
A friend of mine was always very sensitive and routinely told me that I had hurt her feelings by doing something super innocuous (or seemingly innocuous). For example, making a joke about a guy she used to hook up with, who she made fun of all the time. Apparently it was mean when other people joked about him because she secretly still harbored feelings for him but just didn't want to admit it so she was protective of him (she definitely expected us to read minds). For the most part, this wasn't a big deal. But then she started running her own company and basically assigned me the role of working for her, even though I never agreed to it. Her company involved lots of events and parties, all of which she wanted me to attend. It was just too much. She also wanted me to PAY to attend, like any other customer. She was filling these parties with people she already knew, who were guilt-tripped into going. If I missed one, she'd tell me I "really hurt her" and she "didn't feel supported." She treated me like a negligent co-founder, when in reality I had nothing to do with this company and never wanted to have anything to do with it.
It also got to the point where she needed me for XYZ all the time, but was never there for me. I have OCD and BDD and I remember going to her for help during an anxiety attack (I didn't even need her to call me, just gchat me, lol). She said "Two words: Who? Cares?" because she didn't think my concern was reasonable. Then, she and a guy she was seeing for 1 month "broke up" and she was unable to get otu of bed and needed me to go to her house, then constantly check in with her to ask how she's doing. She even got mad at me that when we were at a party, I talked about "mindless things" instead of focusing on this 1-month relationship the entire night to ask her how she was doing. ALL of her problems became #1 major priorities for anyone she knew, but other people's problems were pointless, apparently.
She also insulted me quite a bit, probably not realizing it. She would tease me about how I had such a hard time making friends and she was all that I had (which made me more dependent on her). She would also joke that I 'looked 30' when I was 22 (she's older than me and when I told her that was hurtful she shot back "What's wrong with looking thirty?!")
I got super ticked off when my dad was diagnosed with a serious heart condition, I confided in her about it, and she was like "Oh, that sucks" and then began literally weeping about some guy she had been dating for a few weeks drinking too much and ignoring her. Like, come on.
I just slowly faded her out. I don't think she understands why, because I think TO HER, she's a great friend because she always attended parties I threw, and was available to hang out. But that's not the most important thing to me, and frankly she was just way too high maintenance for me to handle. I began to dread seeing her after a while because EVERY DAMN TIME i saw her, she told me how I apparently deeply hurt her with something I didn't remember doing. She's done this to other people too, and they also faded out.