Your husband WAS wrong, and if he won't admit it, you have a long road ahead. Maybe you did something that did not satisfy his selfish needs, but that is still not an excuse for HIS actions, and if it were, it is still an excuse and still wrong. I encourage you to do everything you can to show him you can still love him despite his mistake, but until he admits he was wrong, he is not going to be motivated to change his behavior and you and your marriage are in danger. My wife did this for a while, but I would not allow her to see it as anything but wrong no matter what excuse she gave me. We are better now only because she finally understood it to be wrong. As Rick would say, until he is truly sorry, and not just sorry for being caught, he is not on the path to maturity.
He WAS wrong!