OP, you asked especially for a man's point of view, so here goes.
I'm a childfree man. I have always known I didn't want children. I have now reached the age of 40 and I still don't. It's not for me. I have been honest in all potential relationships and obviously my dating pool is pretty tiny. I have had two long-term relationships. The latter with a childfree woman, the former with someone who knew my stance right from the get-go but we split up very acrimoniously after 3 years because I didn't want children. She was convinced I would change my mind and it was MY fault that she "wasted" 3 years of her life loving me. I was a "totally selfish bastard" and - the usual favourite - "if you REALLY loved me, you'd change your mind". Funny how that one gets thrown at childfree men by women. I don't think they'd react well if a childfree man threw back "well, it works both ways if that's your attitude - if you REALLY loved me, you'd change YOUR mind!"
Some men DO say they don't want children and later go on to change their mind and have them. But many, many do not. Or they only have children to please a partner and the relationship ends shortly after the kids come along which isn't good for anyone but especially the kids. I don't actually believe it is right for EITHER partner to agree to kids just because the other wants them if the other partner is merely ambivalent. Both partners should absolutely WANT them.
He's been honest, albeit he had to be chivvied into it. And before the relationship got really serious (I assume you hadn't already moved in together after 8 months?). It would have been appalling to leave it any later. Some people say they don't want kids right at the beginning, others leave it a while, because different people take different lengths of time to determine whether dating has relationship potential, short-term, long-term etc.
But, can I please say one thing to everyone? The guy himself said he was selfish for his feelings. His feelings are totally valid. It is NO more selfish to say that you don't want kids than to say you do want kids. It's all about you, whichever way you fall.
Good luck OP. You've done the right thing. For BOTH of you. Please move on and do not think he will change his mind.