You could choose not to resent him, since he made his feelings clear from the outset, and indeed compromised his feelings to support your wish for a child - presumably because he loves you enough to agree to make you happy rather than stick by his first feelings. Do you love him enough to be happy and celebrate your little girl but not put pressure on him? Or do you love the idea of another child more? In which case, maybe you should leave now and seek a father for your next child.
That all sounds a bit horrible, doesn't it? But it is a way of looking at it.
For now, enjoy your baby, enjoy being a parent, and allow him to enjoy being a new parent again too.
He made it clear from the start. People do change their minds, and who knows, maybe as your baby grows he will be happy to have another. But if he doesn't it is not fair to resent him for it, and it will be YOU causing friction, not him.
This is all easy for me to say, I admit. Although i had some wistfulness that I would like another when DS was about 1 or 18m, we let the moment go, and while sometimes I think 'what if', I find it a very happy experience having one child. Not everyone feels like this.