My heart is breaking for you! I really hope that whatever comes from this situation, you come out on the other side a stronger person. I know you will. I cannot imagine what you are going through or how you are feeling, but what I do know is you do not deserve this. If he is not willing to do WHATEVER it takes to make things better for you then does not deserve you. You are a beautiful, intelligent woman who deserves someone that brings just as much heart and love to the table as you do. I personally applaud you for standing up and calling him out. Even if it was just "flirty emails" it was bound to lead to something and at the end of the day, if he is willing to do that THE DAY AFTER YOUR WEDDING, what else is he willing to do.
Wishing you the best!
Stay strong. We are all pulling for you!