I am a cosmetic chemist, so here goes: First, in the short term, everybody who's posted so far is right, you're just going to have to cover it up for the wedding. Lasers would probably do a great job of clearing it up in the next couple of months if you could afford it. Most importantly (and very cheap), have you tried sunscreen? It is the most important thing you can do for any pigmentation problem. It obviously isn't a magic bullet that will fade your mark overnight, but without it, you're not getting the full effectiveness of anything else you're doing.