What DeeDee said. With bells on. Listen to that! I'm 46 and know 3 women this happened to. One had even had an abortion after the 'd' partner pressured her into it because he wasn't ready/didn't want kids. Now it's too late for her and he has 2 with another woman and is Mr Family Man. Imagine how that would feel?
'He's tried to persuade me it'll be just as fun being a cool auntie but that's just not the same.'
NO, NO, NO! Not the same at all, you know it, he does, too, he's stringing you along.
'I don't think I'd ever be able to bring myself to leave him but now I've just got this sick feeling in my stomach that I can't be with him forever if I ever want kids. Do I wait and see if he changes his mind as he gets older? Can I get a mortgage with him with that hanging over my head? '
Nope, you don't hang around waiting and hand over your fertility and potential for children to a person who has been telling you he never wants them. You don't get a mortgage with him. In fact, you end the relationship.
I got divorced when I was 30 because my ex h, by then 34, decided he never wanted children. We had a mortgage and had been married for 8 years. But this was a dealbreaker. I had to at least try to have children. If I tried and couldn't, it would be one thing but to never try would have eaten me alive.
2 years later I had DD1, the first of 3, with my now DH.
Best decision I ever made.
Get out now. Don't waste any more time.
'I understand how you feel about never having children. I respect that. I respect what I want, too. So I need move on.'
And do NOT fall for any stringing along tactics like, 'Okay, I'll want them, but in 5 years.' or 'When I'm ready.'
Not good enough.