Great advice from Gypsy (and I am in the alt world).
Gardener, these types of days ARE going to happen. Like AAK said, you ARE human. Just accept it, and move forward. You cannot do anything about the past. And if you worry about what you did or did not do, that is just going to take you down further. We ALL could look back and see things we did wrong, and we would love to go back and change that. But we can't. All we can do is become the new person who may or may not be good enough for our spouses.
Funny thing is the more we change into really great people, the more WE have to wonder if our spouses are good enough for US.
Hang in there man. I know you won't let this get you down for long.