I[24F] love my partner [30M] but I don’t desire to have children. How will this end?

We’ve been dating for a year, and whenever the topic of kids comes up, I clearly state that I don’t want children and have no interest in motherhood. He doesn’t take me seriously, believing he can change my mind or that I’m open to it. I often explain, “I don’t want to be a mother because I know I’m too selfish and wouldn’t be a good one.” His response is usually, “You’d be a great mom, I can see it.” I plan to have a serious talk with him about this soon. The only way I’d consider kids is if my partner takes on most of the responsibilities. He says he’s willing to do more than his share, but honestly, that feels unrealistic. I know I’ll get flak for this, but I am selfish. I’m not willing to give up my career, freedom, or lifestyle for a child. I fear I’d end up doing it and resenting them. I understand a child needs both parents, and it would be unfair to bring one into the world without loving them fully. I know what I need to do, but I’m curious: has anyone been convinced by their partner to have kids and ended up miserable? Is breaking up the only solution? I’d hate to be the reason he misses out on fatherhood because he loves me too much to leave.