Sorry for you. I've been many times in those situations but had the chance to have the "happy end" if I can say. That moments are in my mind forever, I exactly can feel the tension/stress of such situation even now when I think of it.
To [UEAK]Clowd, After many years of searching solution, we found, it's modern psychotherapy such as emotionnal,cognitive and behaviors treatments. But all psychologist arn't equal even if they pratice this kind of therapy.
So tell her that you can't help her more than being a friend but that (if you want) you can help her find a good psychologist that do the speciality I describe. The only problem is to find one who's have a good balance between listening and behavior exercices.
One thing I want to say is that all psychiatric drugs and psychanalyse ala Freud are the past of psychology, it's like alchemy is the past of real science such as modern physics/chemistry. You cannot break bad habits (including seeing only negative thing in the world, litterally) just by speaking, you need training. If those therapy never ends, there's a reason, they don't work!!
I think most metal chick need to see fucking psychologist to solve there problems, that's all. They aren't bad people, just desparate ones that make wrongs choices.
So don't take this for you, you're the one on what things have cristallized at this moment, it's not your fault at all,that comes from her past, just help her find a fucking good psychologist, and in a year or two you'll find a cool girl where now you only can see shitload of problems.
Just don't waste your time with bad psychanalyst/psychiatrist, find one like I described that will fix problems effectively, for real.
Besides, good jokes around here! lol