I know things are rough right now. You probably want to curse, yell and scream about how bad things are between you and your W.
Do that here.
If you direct your anger at your W, things are going to blow up and get out of control fast. Don't do any more damage by starting fights, calling names or worse.
Leave her Facebook and email alone. It only makes you look crazy when she tells her friends and family what you've done.
Be the better person. You may not be able to save your M, but at least you can hold your head high.
Do something for me.
Take a break for 24 hours to let everything cool down.
Don't talk to her, email or text her. If she tries to contact you, let it go to voice mail. If she confronts you about being out of contact, tell her you needed some time to think, then walk away.