So sorry for your loss and then having to reschedule your vacation. That's quite a double-whammy!
I'm guessing maybe there aren't any discounts available yet for your new dates. I'd wait it out a bit, hoping a discount comes along. But also consider some other options: changing your resort, drop hoppers if you have them, reduce the number of days (either in the park or overall), drop the dining plan as you may be able to do some other cost-saving dining.
Good luck with the reschedule and enjoy your vacation!