Thanks for helping us get a better understanding of the back story.
Others will be along to add their support.
Again, what are you doing to ensure you are open and transparent to your W. Even if you feel there was nothing wrong, she does. That doesn't make either of you right or wrong, just what it is.
Is there anything that your W is asking you for at this time? Any complaints now, or in the past? The key here is, become a better man and one that only a fool would leave. This is for you, and if it can help save the M, that's the bonus.
Keep posting, even if it is just to journal and vent and ask questions.