if you truly understand what we are saying and if you truly "Get it" and mean it
I agree, and you really have to get it, or it will not be genuine.
Just a few days ago you were harboring some very bad feelings toward your W. Maybe you need a few more days to absorb this information.
Like 25 says, don't say anything to your W with expectations.
When you're ready, this could be very healing for both of you......but it doesn't mean it will get the two of you together. But for now, finding peace between & your W is very much needed. There's so many facets of grieving, you don't need this part.
Don't forget, when you are ready to say something about this, it doesn't mean she'll be quick to forgive you (any more than you are about the A).
IMHO, it's not necessary to voice any part about her turning to OM. You want her to hear it without veering off into an old argument.
This may even need to be delivered in small parts at different times.
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!