Drunk And Cheated

my husband of 12 years 10 @ the time was working out of town and went partying with work friends and got super trashed. He normally doesnt drink. While sitting outside some chick came up to him and apparently came on to him he doesn't remember much but he knows he slept with her or at least started he woke up fully clothed at the co-workers house who had the party. He just told me 2years later because he felt it was keeping us from being close. and if I chose to stay he would be a better husband than hes ever been.He seems sorry but I feel disgusted and betrayed. How do I get pass this we have 2 kids he has never done thos before and said if he wasnt drunk it wouldn't have happened. my cousin says he should get credit for telling me and wanting a fresh start but I dont know.