I think the answer for me anyways is kind of said from some above. Don't put so much stress on it.
If you are looking for like a few fun times with another AB/DL, sure, there are meetups or munches that are for that. But a long term relationship maybe is something that should stand on other things and the "diaper stuff" shouldn't be that important. I know posting that here seems contradictory, but I really think in my own humble opinion that putting so much importance on the diaper stuff, is going to either lead to something unhealthy or hurt. Especially if it is a kink or fetish based thing.
I am not saying having this thing, embracing it, or accepting it is not important. It for sure is, and having someone else can for sure help. But I'd advise just putting yourself out there, focusing on just finding a relationship first, and bringing up the diaper stuff later. If they are for it, cool, and if not then you always need to respect peoples boundaries. I think more people than most are open to try stuff like this, much more than we think they are. From my experience I have met plenty of non ABDL girls who were very "vanilla" to all this stuff, but with a little time and understanding they were willing to give it a try. More often than not, most said they really did enjoy it and would be willing to do it again for me because it made me happy. If you can find someone who opens up in that way or develops an interest herself, that's great. I just think those who enter into a relationship with ABDL being one of the pillars the relationship needs to stand on doesn't often go well in the long long run. Because I have seen that too.
Again, this is just one persons advise online and at the end of the day you need to decide what's best for you. I would always be happy to talk more about it in chat and offer more support and advise if you ever bump into me there.