Wow that's terrible. I can't say I can entirely relate to your loss or disappointment (probably putting it mildly) but try not to let the "fact" that she left because of your ABDL get to you too much. I know that's way easier said than done. But you did your part. You were open about it and included her in it as well. It isn't fair to say you'll love somebody completely inside and out, take those vows, and then change your mind later down the road. I don't know all the details, but to me that sounds like BS. From what it sounds like, you were unaware that there were any real problems in your marriage until you discovered the affair. If she was becoming unhappy, she should've established some serious communication to try to resolve whatever issues she had. Not just jump into somebody else's bed. If my assumption is correct, it sounds like she may have more problems with herself than she has with you. Especially if she's trying to reach out to you again. It doesnt sound like she's very stable. And that's not your fault.
Don't be too discouraged about finding someone else to spend your life with and share these interests with. It might not be as easy as bumping into your soul mate at the super market. But there are a lot of online dating options for people in the ABDL spectrum. I've read many forums where people met their spouses online and they couldn't be happier. You don't have to be scared of hiding these interests forever. Someone is out there that's looking and waiting for someone just like you.
Unfortunately though, the only thing that can fix heartbreak is time, and that sucks. But in the meantime, try to take this opportunity to focus on you. What makes you happy? Things that don't necessarily require another person. Take note of some of the things in your life that make you unhappy. See if there is anything you can improve on, or change entirely, without it causing too much emotional, mental, or financial stress. Something healthy that makes you happy and gets you out of your comfort zone a little. It could be anything. Go on vacation. Join a swing dance class, or a chess tournament. Take up painting, or learn to play an instrument. Spoil yourself with a new ABDL toy or diaper or clothing etc that you've been eager to try. Change your look a little maybe. Sometimes looking like a brand new person can make you feel like a brand new person. (Just don't try erasing who you really are.) You can even apply at other jobs, regardless of whether or not you think you might actually take the job if one is offered. Sometimes it helps just knowing there are other options out there, even if you're not quite ready to take them.