Friendship

I have a friend and she has severe moods swings and lie for no reason at all and then tells me she was just lying and then lie about the same thing again. she lies to try and make me jealous, she like to argue and she tells me she gets off from arguing. she is extremely needy and says the world revolves around her. She at times have tried to humilate me and have done that to other people who have been close to her. One minute we can have a normal conversation then she will turn on me and call me names like bitch, devil evil and a demon then after all her rage she will go to me are we still friends and lets be friends like everything is normal. she has ask me not to give up on her because people have given up on her on the past because of the way her mind works. She sometimes acts likes she has remorse for her action but I feel sometimes she just acting, she can be very manipulative because I know I've been manipulated on number occasion to do what she wants and gain financial gains from me and other people even though she has money in the bank. I try not to let her do that to me anymore. she seeks sympathy from other but than acts like she don't want anyone to feel sorry for her. She always telling me that I feel like I'm better than her because I go to school trying to finish up my bs and I'm in the military. she has no job and she has two kids and at times I feel when the kids are sick she tries to make their health situation worse than it's really is so I can talk to her, or sometimes when I tell her that I don't want to be friends she uses the kids against me and say she regret making me the godmother of her son and I don't care about her kids. I feel stuck and I want to help her but it feels like I'm being drained by her, because at times I have to think before I speak because I don't want to upset her. she has wished death on me and threaten me but never took any actions I assumed she was just mad and said that. she also have wished death on another person who was very close to her and that was her husband. I try to be there for her when I confront and tell her what she doing she says I'm trying to make her seem like she's a horrible person. she always saying she not the worse person in the wall and she's only human and she's a good person. I've know her for two years now and I know she going through a lot because her husband died a year ago but I feel that she uses his death a crutch for sympathy and to get things from people. her husband died in a car accident on a highway but she expect me to pick her up and drive her to come to my home when she doesn't want to be at her house. I live 48miles from her and I've been driving her back and forth for awhile but I'm tired of doing it. she told me she was scared to drive on the highway but she drives on the street and other places where you have to get on a major road to get to certain stores which she like going to. she yells at me at at time be verbally abusive to me like I'm jer personl punching bag her husband use to be the person she would always pick anarguement with but since he passed away it's now directed towards me.she also have left me crazy voicemail that are harsh and then when I confront about it and let her hear herself she tells me she don't remember leaving me those message. I love her and care about her welfare but I feel like I'm going crazy because I bend over backward for her and she tries to say I'm not a good friend everytime I try to walk away. I want the friendship to end because I've been stressed but I feel guilty if I abandoned her. I ask her to go get professional help she admits there's something wrong with her and she wish she wasn't like that but she hasn't gone seen anyone. one minute she admits she has a problem next minute she says there nothing wrong with her. I know I typed alot hoepfully you can help me with my dilema