Ttc, depressed, just want support

I’ve been trying to convince for a while now and I went to the gyn and found out I have PCOS. My boyfriends always wanted kids and when he heard the news he was devastated. I am on medication and we are still working on it. I just feel that I can’t make him happy if I can’t have kids. Why does it have to happen to me? Everyone I know has kids like nothing. And I have to be the person who is struggling. I feel like I want to leave him At times so I can find someone who can give him kids. I want him to be happy and have a family. I told him if I was told I for sure couldn’t have kids I’d leave him. I don’t want to be selfish and be with him while he could be with another girl having a family. I love him and therefore I want him to be happy. He tells me he won’t let that happen and he’s fine with it but I can’t do that. I can’t be selfish.