First off, my sympathy. Six years is a long time to be with someone, and even if it were just a pal (let alone GF), it would hurt to lose them. Unfortunately, love has to be a two way street. I hope that if you just give her a few weeks, she\'ll realize how much she loves you, and how much she misses you in her life. If she doesn\'t, well, then it\'s probably a good thing you found out before you tied the knot.
If you have common friends (especially girls), try and get their take on the situation. My last serious GF\'s girlfriends were a wellspring of usefull relationship info, cause my GF talked to them about everything. Use the time to get reaquainted with all your buds. Keep busy, don\'t wait around at home (hoping she\'ll call), just try and move on with your life, and don\'t dwell on what you can\'t change.