@Glitterwolf: I said she wasn't/couldn't be responsible for everything (at work). And yes, I do think it's a case of being better of without her.

@hgpd: Her response was very obviously aimed at me. It may have been HER issues causing her to behave this way, but she was intentionally hurting ME. Yes, she was on edge with other people as well, but none of them got the hate directed towards them that I did. I guess I was more of an easy target?
I don't blame myself anymore. The only thing I could have done differently was asking her sooner what was wrong - the longer I didn't, the more tense the situation became. But I know it was not my responsibilty. If I had said something that upset her, she should have talked to me.

But I think my reasoning for blaming myself was: I am the one that doesn't have any friends, people always abondon me, so it must be something wrong with me.