Try not to worry about having kids... Potential to not have kids isn't a reason to stay if he isn't serious. Women are having kids later and if not there are many options to have a kid in your life.
Food for thought:
Growing up my dad was (and is) an alcoholic. I love him very much, he's the rare alcoholic that never missed work, always paid the bills and was never mean or violent. BUT... He was never 100% present, he forgets our conversations.... Which really hurts. Growing up as an only child raised by a single alcoholic father (ah the 80s) I have learned that to be normal and subsequently almost all of my relationships were with varying degrees of bad behavior around booze. I think some of it is becUse I'd be embarrassed to bring a normal person to visit him. (He's very sweet but he gets druuuuuuuunk every night and my step mom does too and she is not sweet)
My dad is great in so many ways... But dang do I wish I grew up without that mess in my life.