I'm sorry you had to do that. You never know what the future may hold for you; she may respond positively now that you've drawn the ultimate line, or you may D and reconcile 6 mos. down the road or even 2-3 years. It happens quite frequently, in fact.
I filed for D on my wife, when she refused to end her affair, and we're still standin', three years and one beautiful new granddaughter later. This ain't over by any stretch.
Try to give grace, and treat her with as much civility and class (without being a doormat) on the way out. It will serve you well in any potential reconciliation -- trust me.
