Most Helpful Guy
You are over reacting - but if you're this much of an insecure nut then marriage is not for you. You'll be divorced in a few years, even more bitter and less trusting than you are now. It won't be good for anyone.
Postpone your wedding until you've learned to trust someone, and learned what are the actual reasons for not trusting a *fiance* as opposed to just some guy in general.