I can definitely relate in some regards.
I've only had two relationships where I chose to incorporate diapers in that way simply because they were the only two women I every felt comfortable doing so with. There was also in each case a serious emotional base for each relationship and a well-established "vanilla" sexual relationship as well. The existence of this intimacy in combination with a deep-rooted fetish culminated in...well, really, really hot sex. For both of us.
As time went on, and more I shared it, the less power it seemed to hold for me while I was on my own. Or so it was at times. It became less erotic and more about comfort, for example, and though it did still turn me on, the physical attachment to the object was not the immediate turn-on, but the implications and significance (imagined or otherwise) of the object (DIAPER) changed. And then that changed again too.
The relationships changed, ended, new one began, etc, and my emotional, sexual and physical responses changed as well. There was a point where diapers during sex didn't really do that much for me if I was the one wearing them (which previously had been the opposite of the case). My fantasies changed.
If I wrote down my fantasies before and after each relationship, it would be a different story. When you experiment sexually with another person, you YOURSELF grow both emotionally and sexually as a person.
It's something to consider, xtrabulk. Just as your sexual relationship with your wife is changing, so perhaps too is your sexual relationship with yourself changing. THESE ARE WONDERFUL THINGS!!!!
And I don't mean that "you're lucky to be able to have that so you better not take it for granted!!"
What I mean is embrace it, give it all you got, and learn as much as you can.
As for the point that most concerns you, to address it specifically-- there is no specific suggestion I can give, I don't think. But you've opened a new door, my friend. Enjoy the new view! There's even more to it than meets the eye . I'm very happy for you!!! Congratulations!!