It sounds like there's a lot going on in her, biochemically/socially/emotionally/etc.... I'm sure you'll get a lot of good advice, and I'd like to add one thing to complement the other ideas presented.
There's a field of personality study called the Enneagram. At its most basic, there are 9 personality types and they interrelate in different ways. There's a test you can take online, but I think the best way to learn "your type" is to simply read over them and consider how you respond to the world, what you most long for from life and relationships, etc. The great thing about the Enneagram is that it gives a portrait of how a person is when they're moving towards health, as well as away from health. So it can be a spiritual journey, a way of self-monitoring, and a way of envisioning what one might want life to look like (so as to counter the despair of "this is the way life will always be"). You can look around on the web, or there are several books ("the enneagram in life and work" is a pretty solid one).
I suggest this because teens sometimes can do amazing things if they sense that they're not being "fixed" but are actually participating in the process of discovering who they are. It complements many therapies and, as I said, gives a perspective that really values the different kinds of people/ways of being. No type is right or wrong, it's all a matter of growing into ourselves.
Good for you as a parent, reaching out to her and to others.