No getting through to him...

I could use some advise ladies..please no judgement or anything mean. I met my significant other a year ago and we were inseparable from the beginning. We did drink quite a bit but I didn't think it was an everyday thing. We found out that I was pregnant a few months later and now I am currently 32 weeks. He does already have a son and he is great with him and I have no doubt that he's going to be great with our son. He's been having a hard time with work and I have been pretty understanding. But we don't have a place together yet and it's going to be really hard once the baby is here because my dad has been letting me stay with him for the time being and I don't think he wants another grown man coming in and out of his house. I'm starting to think that everything my boyfriend says to me is just promises that he will never be able to fulfill. It seems like he is still caught up in the party scene even though he's in his upper 30's. For example..we came to my parents lake tonight and he told me at midnight that he was going to come up to sleep with me because he knew I was tired. Well it gets to 2 am and I decide that I'm going to sleep without him. It's now 3:20 and he hasn't came up he's still down partying. To me it seems like he doesn't take my feelings into consideration. This is a nightly thing. I've worked my ass of for the past 6 months to save up as much as I can for my baby boy and he hasn't done anything. I've tried talking but it turns into a huge argument. I know I should probably leave but I do love him and I want us to be a family. Does anyone have advise on how to make it work or how to leave and get through it? And am I over reacting? Thank you...