Unfortunately, it's probably not possible to get your villagers back, unless you had a backup of your savegame file.

Were you monitoring their health and their food supply? Did you change the time on your computer clock? Villagers don't usually all die without a reason. If you haven't done anything with the game since it happened, you can find out why they died (and see the time stamps that would let you know the computer clock's status). This answer in our Support FAQ has information about how to access the game log for VV2.