"The affair is 100% my fault. I have taken responsibility; not sure how, in your view, I haven't. "
Because before you even wrote this part you spent a whole paragraph discussing problems your W had or your "shared" problems. She might have had communication problems, but she didn't go after another person. And you did it TWICE. That's the telling part that you were and are the one with the problem.
Bottom line is that no matter how badly your M is going you don't find comfort in someone else's bed. AND because your W was betrayed by her XH, you did worse by betraying her twice.
I have no doubt that your M can be saved, but I'm not sure it's worth it. I mean, how does your W know that you aren't going to cheat on her again? How do YOU know that you're not going to cheat again?
You say that you've suddenly understood why you did the things you did, etc. But words don't mean anything. Actions do. And your actions showed that you couldn't keep your word. So what assurances does she have that you aren't going to do it again if she comes back?
That's what she's afraid of. Transparency means nothing for now because it's the fear of FUTURE hurt that she's afraid of.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.