OP is searching her heart, agonizing, wondering if she can or should give up children to have him. She is looking at everything in her heart.

He, however, as far as we know, seems not to be doing any agonizing.

One way to look at him is to say that he is true to who he is.

Another way to look at him is to say that he doesn't care enough about her to even try.

Someone above suggested a trial separation. That sounds good to me.

I think that OP would do well to leave this guy for (say) six months and then see whether or not she can in fact live without him, and see how interested he is in waiting for her.

During those six months, both of them find could find ways to spend time with children. Her, to fully explore (as best she can) whether she can live without them. Him, to fully explore (as best he can) whether he can live with them.