The wondering is normal, the more you focus on improving you, the less wondering you will do. It takes time. Now listen, as of right now who knows about "somebody else." It happens here sometimes. If you are ever hit with a bomb like that or about something else, DO NOT react or confront right away. ALWAYS take a few days to think things through and cool off.
The only person you have ever had control over is you. This crap sucks, I know, but there really is nothing you can say to her at this time. So use this time to improve you. When you change permanently for YOU, she will notice, I don't care how she acts or what she says, she WILL notice. The same thing has happened with my children too. You be their rock, they need you now more than ever. I think it is excellent that you are becoming closer, keep your focus on your kids and you.
One last thing, Your w knows you better than anyone. You have to try your best not to let her see you negative, bothered, angry, whatever. Positivity ONLY when she is around. If you have to have one of those "moments," which btw are totally normal and healthy, do it by yourself.
