Just need advice

Angel #6 sweet babies 💊 hypothyroidism

So I know that most of you probably don’t have teenagers but any advice you want to give I will appreciate. My daughter just turned 15 and for the past two years she has given me and her step dad pure hell. Her real dad is barely around and never has helped me financially or any other way although his parents have always been there and have somewhat helped. Anyway she has been sneaking out , smoking pot , having sex, and being completely disrespectful to me and my husband. She has “attempted Suicide” twice. The first time she cut herself because her boyfriend broke up with her the second time she took six pills because I took her phone then got scared and told me she did it. Both time I had her admitted to the mental heath hospital because I believed she was using that to manipulate people into giving her what she wants. She is in counseling. Recently I found out she snuck out with a guy had sex with him for weed and two hours later the boy was shot and killed . I’ve had to call the police numerous times to bring her home after she sneaks out. Then two days ago she got mad at me because I wouldn’t let her boyfriend come over or spend the night so I took her phone when she tried to take it from me I threw it and it shattered so of course she starts acting crazy cussing me out telling me she wants to die because of me all kinds of horrible things. Well I have a two year old who is terrified at this point and I’m pregnant. So to calm things down I put my hands on her shoulders and turn her around and force her into her room and shut the door. I told her if she doesn’t stop I’m calling the cops. She started beating herself in the chest and face and says she’ll tell the cops I did it to her. I ended up calling her grandpa to come get her and now she’s saying she wants to live there and I also think she’s trying to tell them that I hit her I have two other teenagers that will witness that I have never put my hands on her or them. I went to the police station that night to see if I could get some kind of help but unless she breaks the law they can’t help. As awful as it sounds I feel like for now her grandparents house is the best place for her. What would you do if you was in my position?