Help!!

Well my boyfriend and I have been together for a little more than two years. I've known him for 4 years but he went to the army and we started dating on his last year of being in the army.. And as you know sex was amazing he wanted it all the time because he didn't date anyone while he was in the army. But now everything has changed, I do everything to turn him on and nothing seems to work. We are trying to get pregnant, but I feel like he is not interested in me anymore, he says he still loves me but I'm not sure anymore.. I love him dearly and want to spend the rest of my life with him.. What is everyone's thoughts?