Sad and frustrated

I don't have a place to vent so I'll vent here I'm almost 30 I've been in some really bad relationships I'm at the point where I want to get married and have kids my boyfriend has kids and doesn't want anymore nor does he want marriage he doesn't get it I love him so much I could see us spending the rest of our lives together. It's a struggle because I want what I want and he does to... any advice