GW, a lot of people on here have been / are in your sitch. Me included. WASs, As, OPs are as common around here as Disney movies around Christmas. Sure, there are unique aspects in every sitch, there's also lots of commonalities. Like Sandi, Greek herself was a WAW too once.
You can't "save" your M by "fixing" it or your W. And as has been posted before, it takes 2 to make a M work even if it only takes 1 to destroy it - you can't "save" it on your own. I know you're having a hard time, but it might be easier if you focus on what you can control, and taking it step by step.
You're not dealing with the woman you loved and married right now, not with an A / OM in the mix. In some ways, your W is already lost, and your M is over. You have to start from that and work towards a chance of a better M.
Me 42 W 39 Married: 11 Jan 1998, T: Since 1992 First Bomb: Sep 2007 Confirmed A/OM: 4 Nov 2007 Kids: D10, S5 Reconciled and together again after (alot of) time and heartbreak. 3rd kid, S, born 2 Jan 2010.