My best friend is depressed and suicidal, how do I help her?

My best friend from high school is really scaring me and I don't know what to do. I don't want to lose her :( Back in high school she seemed so happy but a relationship gone horribly wrong has left her depressed and unable to trust anymore. She is clinically depressed and bi-polar I think and does take medication. her parents are...fowl, they constantly put her down and the whole family seems to treat her like crap. They forced her to drop out and she had a 4.0 gpa right now she's been going to school and seeing someone else but things have been getting worse. For a while I lost contact with her and during that time she cut herself up several times. She's told me things like how she hates society and would rather be alone and that she can't trust anyone and when i told her I loved her and cared about her and that I wish she wouldn't say things like that she said she couldn't believe me...like she was afraid to be hurt again. Over the past couple days a lot of things have happened and once she tried to get help and when she told the doc (at a drug abuse clinic because the other one was closed) her mom went and said she was lying so the doctor didn't believe her when she said she was suicidal and they just gave her more meds when the other people there could see she wasn't joking. I told her to be strong that things would get better when she was able to get away from home but she said she'd kill herself before that happened and told me how her wrists are screaming for her to just end it all that nothing's worth living anymore and she'd rather be dead than put up with the crap from her parents anymore. I've tried everything and it seems to get me no where, I don't want to suggest she get help because it may make her mad. I don't live near her and cant get to her because I don't have a car but i'm scared for her she used to be so happy in high school and now after all the trauma she's endured (some of which can't be named) she's gone downhill and i'm afraid she's quite serious when she says she's going to kill herself soon. what can I do?