Like you said, confidential information should remain confidential. It is really rare to restore a relationship to its original state of a confidential matter is leaked. Even when the person says he or she has forgiven, he or she will still be selected the type of information to disclose to you. Yes, people are different. There are those who care much about confidentiality and that is exactly the person you dealt with by revealing his confidential matter. In any case, it is good as you apologised, you were also a victim as the one you revealed it to went ahead to betray you. But so long as you are sorry, you just have to move on. He might take you back as before in the future if he notices that no one holds confidential matters like you did when you were close except for that singular one. Sorry is truly magical and everyone knows this. Thanks for your entry