Neither of you are being unreasonable.
There is not a right view and a wrong view.
There is only his opinion, which is right for him.
And your opinion, which is right for you.
You cannot make someone have a child that they don't want. It is wrong to bring a child into the world when one of their parents does not want them.
You have the right to want another child.
But you don't have the right to force another child on someone else.
So, really, this isn't about who is going to win. If you can't agree, then you have to decide what you want more. Another baby may mean finding a man who wants one. That's fairly drastic.