Maybe if you alter your focus from the act of sex to a greater bond of physical intimacy. My W's biggest complaint other than I always wanting sex was that we couldn't touch without it always leading to sex.
So I concentrated more on the hand-holding, the embraces, the back rubs, the caresses, the massages, the gentle squeezes, the cuddles, etc... I started to find this just as desirable ... and when it comes time when she is ready, the sex is usually more intense.
Maybe one way that might help you look at it is ... work all the angles above (which will take days or even a week) as a way to build up to the physical act. The result is while you may not gain any more frequency, the way in which you are being physical in between may be more enjoyable to you both instead of the building of resentment.
It also opens the door to more creative ways to be together which can add more fun and pleasure too. For instance, we would never take showers together, now we do. Once or twice a week during an evening, I started shaving my W's legs for her, sometimes including an upper trimming, which sometime can lead to ... well I think you can figure that out.
OK, that's probably more info that you need to know, but I think you can get the point...
