My Teenage Daughter constantly bullies and terrorizes me...what can I do?

I have a 14 year old daughter who is a mess. She is bulimic, she smokes weed, she hangs out with kids who do the same and more. She constantly berates me and criticizes me for being a stay-at-home mom. We bought a manufactured home and now she calls us "trailer trash." She complains we don't have enough money for anything and she tells me I'm a "loser." She wa sin the eighth grade and couldn't handle that, so she begged me to homeschool her. Against my better judgement, I did and she refused to do any of the work. So, I have done the work because I don't want her home another year. I know it was wrong, but I knoew she wouldn't repeat the eighth grade and I couldn't stand to have her here for another year. Every day, she picks a fight with me, putting me down and yelling at me for whatever reason. She acts like she's going to hit me and tries to break my door down if I go into my room. I've threatened her with poilce, but she tells me she will tell them all sorts of lies about me and the family if I call them. I honestly don't know whta to do with her anymore. I would send her somewhere if I could afford it.