LOST AND DONT KNOW WHAT TO DO

I’m currently pregnant and stay with my family it’s my mom,stepdad, brother, step sister, and me of course well my stepdad does hard drugs and mom drinks alot my brother smokes weed but that’s about it well a week ago my bd stayed a night with me and my parents was in a real bad arguement that woke the whole house up well now my bd saying I need to move or he will call cps after I give birth or he’ll fight for custody well if he fight for custody there’s a chance they’ll take my child my sister and her baby which I find that real selfish I’m lost don’t know what to do and it’s stressing me out to the point Where I have became real depressed I just need some advice