No sex!

My husband and I have wanted to have another baby for years. I have had some medical problems that have made it hard for me to conceive. For the last few years my husband has not wanted to have sex. We have sex about 2-3 times a year. We have both gained weight (him much more than I). He finally told me he feels like he's too big and hasn't been in the mood because of the weight. I told him his weight gain doesn't matter to me but he still hasn't wanted to do anything. He is 40 and I'm 34. We don't have a lot of time to have another baby. What would you all do?