Hi Huddy , firstly , sorry that you found out about OM that way , that had to have hurt. As an outsider to your sitch I'm surprised it took this long. As hard as it seems , once they decide to go they are done with the marriage and in their thinking they are single and act that way.
Secondly, could this be the push you needed to move forward with you life. Again as an outsider you seem stuck and need to accept what is.
Thirdly, your a clever lad and don't need me to tell you that the exchange with W was unproductive and really dosent need to be repeated. It's done now and wont affect anything long term either way. Learn from it and move forward.
Again , this is a painful revelation but it's reality. Posting a bit more often may help you because there are some really helpful people on here that can offer constructive advice.
I've said it before and i will say it again , you deserve better mate. Step back and ask yourself if you really want someone with her qualities ? The OM is not winning any great prize. Who she is now is not who she was before.