MC doesn't work if both parties are not very willing to save the M.
She can't use the excuse of needing space since you're not there to crowd her. How often do you contact her? Time to stop. Don't text or email except to talk to kids.
To tell you that she has "thought about cheating" is her way of preparing you for the fact that she already has cheated.
I was almost a WAW. I had an EA. Therefore I think from that POV. I believe that a WAW in an A has to suffer the fear of losing something precious to her before it pulls her out of an A. Sometimes that does not happen soon or easy. What is the most precious thing in the world to your W? Before you answer, I want you to know that she has changed from that young girl you M. I doubt you would believe all the ways she has changed since she has become a WAW in her heart. So, don't compare her to how she used to be b/c that will be a waste of energy. You have to deal with how she is now.
Another thing that will help the W cause her to have a change of heart about the M, is when she thinks the H doesn't want her and is doing fine without her. No anger, no screaming matches, no getting even......just let go. Drop the rope. If she thinks that you do not want to be with her and she sees you moving on...happily.....that will get her attention faster than any tactics.
You have three children to consider. What will you do once you retire? Live in the same town? Will you get 50% of custody? Once, those children were the most precious thing to her....but maybe not so much now. Shocking, but it happens. Mine were important to me, but I thought I had spent most of my life for them and I wanted to be happy for once before I died (mental attitude of a WAW). Shows you how the heart/mind can be twisted.
I strongly suggest that you stop contacting her. Make her wonder what you are going to do. When contacting the children, do not tell them anything except you love them and they are going to be okay. Talk positive to them.
You are physically detached and now you will have to work on emotionally detaching. If she bugs you about moving on with the D, I'd tell her she can have her D but not until you get home b/c you have plans. Don't tell her what those plans are. Be mysterious. In the meantime, get your finances secured b/c she'll likely try to wipe you out. Don't warn her, just do it.
This may not sound like DB to you, but that is honestly what I'm trying to help you with.
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712