I’m scared for my kids, I’m scared of him getting custody

I’m literally due any day with our 2nd child. Our relationship has been shit lately and just got worse. I’m basically only staying with him because I don’t want him having our kids alone. He drinks, basically everyday. He drinks and drives. He will come home drunk and he will have his(not ours) kid with him. He lets his friends roadie in the vehicle with his(not ours) kid. He is constantly “mad.” He gets mad if our daughter(1) spits out her food, doesn’t go to bed easy, throws her food, whines, etc. He constantly neglects his daughter(9) yet she idolizes him. He has her every other weekend and she sits in the living room by herself while he ignores her in the garage. He has let his ex gf kid (11) watch his kid(5) so him and his gf could go to the bar.

I know this is a single mom page but I’m basically posting on here seeing if any other moms have advice. My state is very mom and dad favoritism. It is damn near impossible to get full custody. I can’t risk my daughters being alone with him. Atleast right now I keep our daughters out of the vehicle with him cuz I don’t let him take them nor does he fight me cuz he rather go drink than be with us. Also when he’s in a bad mood I just leave. So staying with him is the safer option for my kids even tho I know we would be happiest if I got full custody. Any mommas live in Wisconsin and get full custody? Just to be clear I don’t know when he’s out drinking because he goes after work randomly and comes home like that. My family wishes I could leave but they also fear him getting custody. I know he would fight for custody to “look good” cuz that’s basically all he is with his kid- an act. I’ve never seen him actually spend time with her. I just wanna cry