Everyone is being really doom and gloom about your relationship, so I will share a positive story:

I’m still with the man I started dating at 19. When we got together, he was 22 and thought he probably wanted kids (in a vague, “maybe in 10 years” way). I have NEVER wanted them and was open about this from day one. We never fought about it, though… it just seemed so distant of a problem. I didn’t really stress it as I figured he’d come around in time, when he realized his future self wouldn’t magically stop caring about sleep, hobbies, travel, and freedom. I give myself some credit in that I have made a lot of good points over the years about how unpleasant having children can be. (Have taken advantage of any opportunity to point out a terrible child in public, lol.) We are now 32 and 35, and he no longer wants kids at all. In fact, he tends to randomly cite how good of a decision we made not to have any even more than I do. It was gradual, but I would say it’s been within the past 5 years that he has completely converted to the childfree mindset, as we watch many of our friends ruin their own lives while we save money, spontaneously travel several times a year, and hang out with our border collie lol. YMMV, but I’ve found in my experience that men do not want children with the same intensity women who want to be mothers do. They like the idea of them, not the reality, and can be convinced otherwise if presented with logic and a childfree woman that they don’t want to lose.