This is a bit of a copy/paste response from a reply I gave to a similar thread. I respond to these because I have been there and know exactly how sad and frustrating it is.
I had a very similar sex life with my ex-husband. It was a major reason for the divorce, because it filtered down into and affected a lot other aspects of our life.
My ex husband was also affectionate and loving but able to lose himself in a moment, act on physical desire, couldn’t talk about sex, use sexy language and so on. I see now that he loved me, but more like a family member than a wife or partner. No one would have believed the poor sex life we had, due to us both being young, child-free, attractive, fit and healthy etc etc.
I have to be honest and say that in over a decade of marriage, I tried in many ways to pull him out of his shell and show him what a fulfilling sex life could be. But he just couldn't do it. Some posters will be blunt with the divorce comments. I would say: do what you think you need to do to give it every shot in the world of working. If it doesn't, you'll know you tried everything. We need to figure this stuff out for ourselves and you're obviously not going to file for divorce today based on comments here! My gut instinct tells me this is too important for you and not important enough for him though.
I am now with someone who pushes me up against a wall to kiss me on the walk home from the pub/ cinema/ restaurant or bites my bottom lip while we're kissing to show me what he's thinking or does lots of other things I wont mention here! Sex is important to me and I couldn't have stayed in my marriage. BUT, I think it will take you some time to see whether or not you arrive at the same decision.