I want children, my boyfriend does not 😭

My boyfriend and I are in our mid 30s. We want to get married one day (we have been together for 10 months but friends for 20 years). I have a child from a previous relationship and a child I placed for adoption. I always thought I’d get a chance to have another child with my future husband. My boyfriend says we will have my one child and that’s enough. He was okay with adoption earlier in our relationship but now it’s a big maybe. It makes me cry every time we talk about it. I don’t want to leave him because we have a healthy positive relationship, but this just pains me. I’m going to bring up fostering and see what he thinks of that, but he said he should be enough without children. This is so upsetting. I need advice please!