You are very deep in the "this was all my fault" stage. The power of being there is that you find motivation to work on self-improvement.
On the other hand, you did not drive your wife to cheat on you -- she made that choice herself. Cheating is often driven by unhappiness and dissatisfaction, but all it requires is opportunity.
One thing that will need to be restored is your attractiveness to your W. Own your role in things, apologize when appropriate, but do not over-apologize. She's still lying to you right?
You need to be self-confident and independent right now, and you need to tread water while her feelings for OM run their course. Her infatuation is not about you -- you are a casualty.
Her feelings of guilt are forcing her to construct a narrative where you are the bad guy and drove her to this. Listen to what she says, validate how she feels, but don't buy into her fictions.
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015
