I don't know your back story, but certain elements of your post reflect similarities to my situation here, also four years out from DDay and headed into divorce.
Again, I'm sure I'm probably missing a lot of facts, but perhaps some of my story may pertain. Truly hope not but here goes.
I'm the BH in our marriage, my stbxx and I's situation is much the same as to what you've described. She wants more intimacy, affection,etc., but most days I look around at our life together and cringe.
In my situation (this part probably not same for you guys) I've asked numerous times for her to get herself into counseling, and she refuses. It was one of the few absolutes that I set forth for R. So (regardless of what it is, counseling or drinking or whatever particular)in essence this is an example of my feelings being invalidated. My other conditions were for her to begin to shoulder an equal share of raising three kids and running a household (I'm always been the cook, launderer, bathroom scrubber, cleaner, handyman, gardener, busboy, dish washer, and breadwinner, etc.) She never met any of these needs, especially during R.
On my side of wrong, she was raised by an alcoholic father who until a couple years ago would drink himself stumbling drunk daily. For her, an absolute was that I never drink. In response, as an unhealthy passive aggressive FU (and definite gut buster) for her not meeting my biggest requirement for R, I made a point to drinking between 4-6 light beers most nights. Rarely ever got a buzz, but you may be able to see how this could become a problem. I stopped doing it two weeks ago because I just don't like what the whole passive aggressive crap represents about myself, and with the impending divorce I want a clear head and to set the correct example for my kids of not drinking, especially when spending limited amounts of time with the kids going forward (split time).
Most days I come home excited to see my stbxw and kids until I walk through the door and it hits me every single day how my needs / feelings / requirements for R haven't been met, and whatever good feelings quickly become replaced with negativity. There are days when I get angry, but I avoid any conversations of "us" or feelings as I don't have anything new to add to the subject from what I've said a hundred times already.
Again, each and every couple going through this may have some different perspectives / details / triggers. The bottom line in the demise of my marriage may have begun with her cheating, but in the end for me it was the utter lack of respect for my expressed needs / feelings and completely invalidated existence within the marriage other than to continue to be a doormat.
Back to your situation: have you met all conditions of R? Have any of his expressed needs been overlooked or dismissed? Sorry for the long post. Again, I'm not sure if any of this even applies (without knowing the back story), just throwing it out there.