My 13 year old was going thru the same kind of thing, and it was driving me crazy trying to get her to stop.
Being honest with her about how what she says affects other people around her... And it seems the harsher I got about the realities of how people react, the more she cried and swore to change.. then the next day she would come home from school telling how someone new wanted to beat her up. She lived for the drama, and could care less about her school work.
Nothing seemed to work till I sat down with her one day and asked her what she really wanted to do with her life. If she wanted to be a mom with a husband or if she wanted some kind of career.
Turns out she wanted to be a lawyer, and that really isn't a realistic option. She is in a lot of special ed classes because she is so behind in her math and reading skills. So I flat out told her that she would NEVER be a lawyer if she didn't change. After she finished crying, I told her that does NOT exclude a ton of jobs in that field. Everything from transcriptionists to police to lawyer runners, etc. That finally caught her attention. Knowing that there were things she could do even with her not reading as well as you need to to become a lawyer.
I think it was that she knew deep down that what she really wanted, she knew there was no way of obtining, so she made her life about the drama that she thought a lawyer would have in their lives. She had a goal that she knew she couldn't reach, so she was a failure from the start in her mind.. so why try.
Teaching her that if she worked hard enough to get into a community college level of education would still open a ton of oppertunity in the field she loves, turned her around so fast it made my head spin. Her grades are coming up.. she has jumped two reading levels.. and all because she now has a realistic and obtainable goal for herself. If she keeps it up, she might just become a lawyer after all :)
This long story might help you if your daughter has the same kind of issues. If they think they are a failure, they will make everyone miserable. Find out what she wants from life.. then be as harsh as you need to be to get the point across that if it is an unrealistic goal, she can't reach that goal.. do it no matter how much it hurts. Then find alternatives that are within reach and in the same genra of thought.. and point her at it.
Basically make it so that she can get where she wants to be in her own mind. Help her find a slightly lower peg on her way to her goal that will make it so she wants to get there.. and knows she can.