Desperate

I am desperate to find a way to help my teenage daughter lose weight. She is 16, is a big girl. She'll never be built small, but she is very overweight. She is miserable, can't seem to stick to a program, and I've tried everything -- Weight Watchers, Nutrisystem, exercise programs, counseling, you name it. She hides at school, won't eat at lunch, hides in the bathroom to change during gym, hates herself, doesn'tsocialize, wears hideous clothes so people won't notice her, you name it. It is ruining her life and mine, too. I've offered to send her to a weight loss camp, but she refuses, saying "I'm not going to fat camp!" She seems to sabotage herself at every turn and is very negative. I am very concerned and desperate. Please, does anyone have any advice? Thanks.