Facebook is a problem. A big problem.

Facebook now crops up in a third of divorce cases over cheating and old flames - Mirror Online

The Real Reason Facebook Causes One-Third Of Divorces | YourTango

It sounds like you guys have reached an impasse. And it sounds like she isn't willing to work through it. It's not a "you" issue, your marriage is an "us" issue.

So, in my opinion, it's time to wish her the best and you guys part ways.