It sounds like you’re doing everything you can. I am so sorry you’re going through this. It must be really hard and scary. How old is your child? Is there anyone in his family who is sober and levelheaded that you could try to reach out to to help you? Perhaps they could be a middleman and talk some sense into this family. Otherwise, I would stay with your daughter as much as possible and call the police if anything untoward happens. That’s all you can really do. Perhaps you could contact and consult a lawyer or reach out to local law enforcement or a women’s DV org to ask what to do. Even though you haven’t been abused, it’s your child and they may be able to point to good resources.