Hmm I disagree that he is being selfish and cruel.
The problem in these situations, is that while you may agree that he has a right to his feelings, you can only feel and understand your own. The same is true for him of course.
I'm sort of on the other side of this. H convinced me to try for a baby. We got pregnant sooner than we had planned on trying and now I am thinking of all the things I feel he hasn't thought about (he has two kids from a previous marriage).
So I share my concerns when I think of them, and he discusses it, and it turns out he has thought of it. He just didn't verbalise it. Or didn't think he had to.
It's possible your husband would actually like another child, but cannot logically see it happening and feels it is not right.
While his wording may have been harsh, it is essentially the truth- you want a baby, but it doesn't mean it should happen.
People say you never regret the children you have, but that is simply not true for people who know they do not want one- for whatever reason.
Perhaps he doesn't have an actual reason, and just feels done. How do you explain that to a spouse that clearly isn't? You can't. The same way they cannot explain their need to you.
It's a no win, no fair situation. And I am sorry you are in it.