Lovethehub has given you another vote for separate now and head the other way is the fastest way back. I don't think it's the only way but I do think it's the fastest and most direct way.
If you choose to stay now, please do this for me: come back in 12 months, 're-read what I and lovethehub wrote above and share your perspective. I will be interested to learn if you feel you should have left.
I should have separated when I was where you are, did not, and have paid the price. I believe we would have been back together now with my W committed and happier than she is now. It would have been the quickest and best path and is not giving up
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