sexless marriage?!

Please don't judge. Just wondering if anyone else has a sexless marriage?..... how to deal with it. A little background: we been married almost four years.Husband is military. He's gonna get out soon. I just joined him overseas about seven months ago. Before that, we were apart about five months. I just don't know how to deal with our sex life. I'm ready to start a family. He says he's ready too. But, it don't help we literally only do the deed like once a month. I tried to ask him if anything is wrong, he says no. He just don't feel like doing it. It got to the point I just don't ask anymore because I'm tired of being told "no". I'm confused because before all this, we'd do it at least twice every other day. Now of course nothing. I've tried everything. From, cooking half nude. Buying lingerie he likes. Giving hints. Even telling him he could do any position he likes. That I don't like..... nothing seems to work. Nothing seems to work. Of course no means no. So I'm not like pushy and ask constantly. Since he says he wants a baby. I even tell him when it's my fertile week. Still nothing. Any advice would be much appreciated. Thank you.