Future hubby doesn't want to grow up (edited)

I need advice, ladies. I'm supposed to get married in 2 months but my fiance doesn't want to act like an adult. Our relationship has been getting more and more rocky as we approach our wedding date and we've "broken up" a few times but we're determined to make things work, especially because we have a young son. Here are my problems though. 1) His job. He works a crappy, part time job. 16 hours a week if he's lucky. Now I am only part time at work as well but I work 30+ hours a week and I have sciatica and I've been told by my doctor to quit my job, but I can't, because we won't have enough money to pay bills/feed us and the baby. He has put in ONE application for a full time job. one. I've applied for every desk job in my area but I have no experience in areas like that so it's incredibly hard to get those jobs. I've also taken civil service exams to work for the state but those take awhile to hear back from. 2) He stays up all night. Ladies. when I say all night. I mean he's up until 3 or 4 AM. playing video games. mind you our son gets up around 9 and I'm at work by then, so he has to get up with him. My fiance is always so cranky in the morning and I hate his attitude most mornings. I've told him staying up that late is irresponsible and he always tells me "This is my only time to play video games". I'm at a loss. someone please help me! Edit: I just wanted to say I do love this man. We got together when we were young and had no responsibilities so we both acted like this for a while. I got myself together (somewhat) when I found out I was pregnant though and he just... didn't. I thought it was just because we were young and he'd grow up eventually but I guess not...