I'm glad you followed your heart about this. To whatever extent your H betrayed your trust his actions prove that he LOVES YOU!!!
I am not winking at his wrong behavior..at all!...but when a very similar thing happened to me with my H the foremost thought in my mind was (for me) 1) I KNOW him and he is a good man...2) Whatever this was that happened (it is hell!)...if I HAD BEEN THE ONE TO DO it HOW??? would I have wanted him to treat me?
Knowing my husband, I figured his guilt would probably be even greater than my pain and feelings of betrayal. DOn't misunderstand...he's had to prove otherwise to me as after a few years trust is still being reestablished.
The action is wrong..however, what is behind the action that promoted it...there was obviously kinks in the armor of our marriage and R that needed to be worked on.
I pray that you are able to work through this and that your marriage becomes all you both want it to be!