Are we experiencing cold feet or something more serious?

My fiancé and I are getting married (we hope) in a month. For the past month or so it seems like things have really gone downhill in our relationship. We have always had our issues but recently the problems seems bigger than usual. After arguing day after day, we finally sat down and discussed our feelings. Turns out we’re both thinking similar thoughts about this situation. He thinks I don’t show him enough love and affection. He feels unloved and unwanted. I agree. I’ve always been very closed off towards him, at least physically, and I can’t figure out why. I love him to death. He’s an amazing man. But it almost feels awkward to be intimate with him! We haven’t had sex in weeks. I have had relationships that all I ever did was kiss, hold hands, caress, and have sex all the time. I need that kind of attention but why does it feel strange with my fiancé? All I can come up with is, maybe we became too comfortable with each other. We’re best friends. We can say/do anything in front of one another. Except be intimate. This is a huge issue for us. He isn’t willing to marry someone who can’t give him what he needs. And I don’t blame him! We are under so much pressure right now because of this wedding. We signed up for couple’s therapy next week but I’m afraid they’ll simply say, “You’re still young. Break it off. Move on with life.” And it’s just not that simple. We have been together 5 years. We have a house together. I can’t imagine just walking away at this point. But is it possible to make chemistry and sparks in a relationship? Or are we doomed?