How can I get my boyfriend to get another job since his income now will not support us?

I am 20 weeks pregnant and stopped contributing 3 weeks ago, since my job was not suitable for a pregnant woman. He promised 4 months ago he’d get a second job and keeps stringing me along promising he will get a second job but has yet to get one. I took a trip to NY 3 days ago and told him I am staying here with my mom if he doesnt have another job by monday. I feel so sad and like I am being too controlling but I also feel like this is the only other option I had to make him realize his irresponsible actions. This baby was not planned and my income was the sole provider, his was our “fun”money. I feel like I have given everything I had to offer for a year and a half before I got pregnant and he should take these next 5-8 months and bust his butt to make ends meet until I can get another job. I have an 8 year old prior and have always supprted him on my own and am not afraid to raise another child alone, if it seems more healthy for my child sake. I really am hesitant to leave him also because I know how much my son needed a father and never had one. I feel so torn on what to do but if I move to my moms I will have a place to stay until I get on my feel again (she does not live in her house) and I will have my immediate families support if I need it. Any one in a similar situation and care sending some advice. Also he is a binge drinker and sometimes spends the rest of our bill money (or money we dont have) on going out all night long with his friends. I ask him if he can just buy some beer for the house and have his friends over but its not good enough! He has to spend 10 dollars a drink at the bar and then drive home wasted, or not come home at all. Then the next day have a very nasty hang over and scream at me and my son all day. i am very sad and need help….