How old is he? I'm guessing I'm his 40s, older than you.
Years and areas can age you a lot and when you know how exhausting being a parent is, you reach a point when the Idea of being a parent fills you with utter dead rather than joy.
I went from being desperate for another child to not being able to imagine worse within 5 years.
Thankfully my OH who doesn't ha e children felt the same. I'd be totally heartbroken if he'd DD ides that he prefered being a father to being a dad but it wouldn't persuade me because I'd rather be without him than live with the guilt of being a crap parent because I couldn't give any longer what a child deserves from both parents.
I find it so sad that someone would give up a perfect marriage for a child though. My best friend was desperate to be a mother until she found her OH could concieve. They tried a number of ivf without any luck and decided to end it there. She went through a couple of years battling depression but never considered leaving her OH.
She then mended her heart and since then has made the best of her life without children. They are the most loving couple I've ever met and she is truly happy now.
Of course everyone is different but there is a lot to lose giving up a solid mariage.
Don't assume you are the issue it's aost inevitable that it's his ability to be a dad again that is stopping him, not your ability to be a good mum.