fiancé doesn't want kids.

My fiancé and I have been together for almost two years. He is older than me I'm 20 and he is 36, when we first got together he said he wanted children. Yesterday he told me that he didn't want children because he done with that part of his life( he has a 10yr old from a previous marriage) I don't want our relationship to end I want to spend my life with him, however I don't want to miss out on being a mother. I'm conflicted and confused. Please give me some advice.