Husband changes his mind

My husband and I got married 4 months ago and been together for 8 years. I have always been on birth control but we have always talked about starting a family and wanting kids, but we did want to wait until we were married. When we got married I stopped taking birth control, which we discussed. Now he is saying he doesn't want kids and can't understand why I do! I feel totally crushed as it is my life long dream to have a baby. We have discussed this for 8 years and I can't understand where it has come from. Any time I want to talk about it he says no and walks off. What do I do?!