Have I done anything wrong?

I don't think you have done anything wrong thusfar, but I would actively try get over this feeling. This stage of attraction is known as the romantic stage, and it is really based on the fantasy you are developing in your head more than the reality of life. Strong feelings of attraction develop in the romance stage or the pre-romance stage, but just think, would you really want a man who has just proved he was unfaithful to one one woman? Sure, he says that was a mistake. So, is he is saying he tends to make impulsive bad judgments? Maybe you are one of them?