Hi newbie. Sorry to hear it's tough at the moment.
Bringing up a baby is tough. I suppose he'll be fiinding all the change hard and may not be coping with it well. But guess what. That's life and it's hard for all parents, mothers and fathers. When you have a baby, priorities change and life moves on. As you say, you both now have responsibilities and whilst it sounds like you are taking these reposnibilities seriously, clearly he is not.
A few things jump out at me.
He says it's "his life". Well you've hit the nail on the head when you say it's now his family's life. YOU ARE NOT IN THE WRONG. You are a team now and he has to choose if he wants to be a team player or not. Someone who doesn't want to a team player has no place bringing up children in my opinion and is ignoring their responsibilities.
Work - His responsibilties include working hard to provide for the family. So he needs to pull his finger out at work and taking it seriously.
Age difference - I'm guessing you're 22 from your nickname. That might be relatively young, but that doesn't mean you know less than him when it comes to bringing up your child. From what you say, you are clearly a better parent than him even though he is older. Sometimes, an older guy can impose his views on a younger partner just because he is older and thinks he knows best or thinks he is in charge. Clearly that is unacceptable.
Respect - it doesn't sound like he treats you with respect, whether that be in front of your child or just between the two of you. In my opinion, a good relationship can only work with mutual respect.
I am a believer that it is all to easy to give up on relationships these days, but the problem with this is that sometimes you can end up putting up with things that are unacceptable from a partner because you want to 'work at it'. So I think you have to stay true to your beliefs and make sure you are not selling yourself short by accepting behaviour that is not acceptable.
Raising children is so hard. I've found it the hardest time of my life and it has put a huge strain on my relationship with my wife. But we recognise this and make sure we both pull our weight, treat each other with respect and put our children first.
Stay true to your beliefs and make sure you preserve your self respect. It sounds like you're doing a great job. Don't be pushed around.
Good luck :)