He wants to break up with me because I don't want to have children

I understand his point of view, someday I want a big family of my own. And it's a huge issue that those who want want children shouldn't have to settle without them. However that being said I do agree that it was wrong of him to not acknowledge what you said on the matter earlier on in your relationship. It seems like he was hopping to slowly bully you into changing your mind and that is completely wrong,