Yeah man, it was a major pita for our two 3GS phones that's for sure. Im guessing you may b too far in for this but if you did the "right click > transfer purchases" on your phone icon in iTunes and then the " right click > back up" in the same menu, then you can always go back to what the device was before you tried to update.
It may take some additional synching with iTunes after the update as for some reason this update wipes your phone clean and then is SUPPOSED to put it all back... SUPPOSED to.