Well, to me, it either sounds like she's in a deep depression, or perhaps she's possibly borderline. I'm not a health professional, so only take my advice with a pound of salt. Did she lose her job or quit? That may sound odd, but it could play a factor. If she lost it, she may feel incompetent right now or that the world is against her. If she quit the job for no apparent reason, that could be symptomatic of borderline behavior. I recently lost my job (it was my fault, however, the seriousness of it involved more than me, and the circumstances surrounding it were horrific, even traumatic.), and afterward went into a huge bout of depression. It was a job that I was overqualified for and was extremely bored with (thus resulting in the negligence to detail that cost me the job). However, when I expressed to my husband how upset I was, he told me to "get over it," making me feel completely invalidated. He didn't mean to hurt me, he thought he was helping by pointing out how beneath me the job was, but in reality, it made me feel more incompetent for losing a job I was overqualified for. Is there any possibility you could have upset her with something similar? Not to say that you are causing her behavior, it's just that those of us with mental issues are usually quite sensitive and frequently take things out of context. Sometimes, we may even unconsciously twist your words to validate our feelings.
Do you have her address/know where she lives? In your shoes, I would try to take the things by to her, give her one more shot at talking to you about what's really going on. If it doesn't work, you haven't lost anything but a few minutes of your time. In which case, I would say you should probably end the friendship just to keep your own sanity. Fortunately, you are in a "chosen relationship" with this person (meaning you aren't a family member, or someone obligated to remain in this person's life.), and have that ability. Maybe just tell her you're sorry if you did anything to offend her and that she knows your number if she ever wants to talk. I'd leave it at that. In the end, it is she, not you, that has to accept her behavior and take the consequences for her actions. Hope I could help.
Hundtoft