Trent is right. She got caught with her pants down (so to speak) but you have admitted that you could have been a better husband too. That doesn't excuse the behavior, but no one is perfect.
As I was learning to deal with my depression, the phrase I used a lot was "my depression is a reason for my behavior, not an excuse for it."
Me: 44, Wife: 39 M: 17 years T: 20 years Bomb on 08/25/09 1/13/10: MC started 1/28/10, 2/8/10: More bombs 8/28/10: Wife moved out No talk of D, no movement