Wow, you made some very good points in your post.
I think it just all depends on your own values, I'm almost 36 and have never been married, I've been dating my boyfriend for 6 years (and living with him for almost 3 years) and Marriage isn’t even a topic of conversation.
If any guy I ever dated asked me to marry him after 15 months, I probably would have panicked and ran, but my relationships never lasted that long until this one (lol)
But my aunt on the other hand, If there is no sign of marriage within the first 7 months, or he shows signs of being flakey in the matter, she dumps him and moves on.
Even though my relationships didn’t last, doesn’t mean I didn’t hurt over not having somebody. It was very lonely for a while. I did have a son when I was 23, but his father left us when my son was 8 months old. I thought for sure I'd be married with 3 kids at this age, instead I have one child with no biological father in his life, we're living with my boyfriend, and despite our decision to try to have one together, life has a different plan, and we can’t have kids together.
So it sucks because sometimes (or too often) life doesn’t happen on our own time line. Nor does it go the way we want.
If starting a family soon is really important to you, and it isn't important to him, then there is a heart breaking decision to make, to either compromise your values, or leave, and neither one is easy.
The only advise I can give (and it may not be good advice since I live such a different life - and yet not all that different) is to just try to enjoy each day you have. You’re still young. Get to know your self, enjoy who you are and what you have as a single women right now, push your self to be the best self you can be (with out him- meaning - do it for your self because he may not always be there) pray about your situation (if you are a prayer), and I believe the best answer on what to do comes when we are being our best with our self and are in a state of peace with our lives.
It sounds like, with you knowing what you want, that it won’t be too much longer before one of two things happen.
But believe me, the only thing you could possibly be missing out on is what you do have today if you're focused on what you don’t have. Life is truly beautiful, there is no waiting for something to happen in order for it to be beautiful, Its beautiful now. And you are Beautiful. And I'm sure if you talked with your friends, they might say there are times they feel they are missing out.
Make life great as a single woman while you’re single.
Make life great as a married woman when you’re married.
And you'll miss out on nothing.
Ok I'm off my soap box. I do believe my words and hope maybe something I said can help, even if it’s to just know you’re not alone.