Wow! That's a lot for you to digest! You sound as if you are blaming yourself b/c you first had a PA. But was it ever dealt with, or was it just swept under the rug in order to continue living together? What happened when she reacted by having a revenge A? Did the two of you go to therapy?
It sounds rather doubtful that her sexual activity ceased after the first encounter. Not trying to make this harder for you, but have you ever wondered how active she may have been before the M? I mean, to have a revenge A is one thing, but to have PA's with seven men at once? Well, we know it isn't love that is the driving force there, b/c women don't love several men at the same time.
I don't have a lot of faith in many of the so-called MC that are out there today. Too many will tell you to proceed with a D to feel better. This isn't just about the M in trouble, your W is in serious trouble and needs help.
I hope you will continue to post and keep us updated.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!