Cheating fiance

I was due to get married later this year but my finance told me he wanted a longer engagement and cancelled our wedding two weeks before my birthday, after spending month dealing with the fallout we were slowly getting back to normal when he changed the password on his phone which I have known for years, also when we went to have sex the first time since the wedding bombshell I started bleeding almost immediately, knowing something was off got checked out I now have Chlamydia which I never had b4 as I get myself checked regularly, devestated as my "fiance" is the only guy I have had sex with in the past 4 years I know he has cheated I looked up his browser history and he has been searching for reasons to cancel the wedding at what to do when you are in love with two people. I'm so devestated I'm yet to confront him because the pain is so much. What would you do?