Well, if you loved diapers before you got married, that's when you should have told her.
But since you didn't, hmmmmm, it might be too much to come right out and tell her everything in one shot. Maybe the thing to do is to try to ease her into it? Maybe tell her you love smelling her panties when she's leaked into them a little bit, then maybe trying to get her to wet them for you, then slowly get her used to the idea that you like pee. Then if that goes well, tell her you've read online about people who are into wearing diapers and that you'd like to try it.
I've told two girls about my diapers. The first one, years ago, wouldn't let me into her pants because she wanted to save it for marriage, but she was OK with me wearing diapers. Then a few years later she decided she wanted to have sex with me. Then as soon as she started letting me into her pants, suddenly she didn't want me wearing my diapers anymore. It was "Now that you have this, you no longer need those!" So I think it was something she allowed to keep me happy while she wouldn't give me any pussy. But once she did, my diapers had to go.
The second girl, of course, is the one I married. By then I'd decided that there was no way in the world I could ever get married to anyone who didn't know about and accept my diapers. When this happened I was in my late 20s and by then had decided that I was never going to give up my diapers and probably would never get married, so, I had nothing to lose. And, lo and behold, she was OK with it.
So you just never know. I have noticed, though, that girls who love kids and want to have babies are--in general--more accepting of us wanting to wear diapers. I once had a girlfriend who had no intention of ever having kids because she "didn't want to have to deal with those disgusting diapers!" So I never even bothered asking her. I knew that idea was dead on arrival. And that's one reason why I eventually broke up with her. Poor thing, I wish I could have told her the truth, but, that probably would have gone over worse than just telling her that I didn't want to go out with her anymore.
Anyway. Good luck.