It seems that most people are leaning toward giving this person more chances and making excuses for her behavior. Perhaps that's because many of us can identify with her behavior, or with the behavior of other mentally ill people.

No one seems to have suggested this person may, additionally, have a personality disorder that allows her to use and discard other people without guilt. I had such a friend once, and finally had to end the relationship because of the continued pain it caused me (identifying with the other side of the relationship). It doesn't look like she's going to change--at least anytime soon.

No one deserves to be treated as you have, Impala. You'd probably be a very good friend to have. Your efforts might be better served if invested in people who are less self-centered than the friend you're discussing.