fiancé problems( long)

So I would really like some honest advice. I'm 4 weeks away from my due date. And I am having some pretty big issues with my fiancé. And I don't want to make the wrong decision. A little back story, we have been together for 9 years and have a beautiful 6 year old, a few years ago he got a DUI and made it very difficult for us. Than proceeded to always go out with his friends and get drunk almost every weekend if not every other weekend. Well shortly after that I was tired of all of the alcohol and the "competition" with his friends. So we broke up. Only for about 3 months and than he decided that he would change for the better and be the father and "husband" he should be. He really did change he stopped drinking as much, and was actually involved in our lives. Well maybe the last year year in a half he has gone to his buddies house and started drinking again, and I have the hardest time trusting him not to drink with this one friend of his. Which he shows me he can't not drink. Some times he has even stayed the night because he drinks too much. And I will admit I get a little crazy, and accuse him of drinking more than he says he does which he says makes it hard to come home to sometimes. Even though he understands. So I think him staying over at his friends drinking and staying the night is just absurd and childish. I don't get why he can't have one or two drinks with him and come home. And he says it's because he likes to relax and hang out "he's only 27 years old" "he's still young" and he wants to be responsible by not drinking and driving but he doesn't want to limit his drinking. This makes me want to leave him. We have been fighting about this a lot and just last night he made it quite clear he doesn't want to change that. He only does this twice a month at most. Rarely more. Rarely less. Am I just crazy? Should I just accept this, or am I right for thinking I shouldn't have to deal with it. Sorry for the length. I'm not entirely sure where to place this, and I made it anonymous because I know a few people on here.