My pre-update world, has been completely scrambled the world chunks

On my xbox one, the new update has completely scrambled the files from the previous version of the world save. After converting the save file into the new format as prompted, the converted file was nothing like it was befode. I just want to be able to load my previous game save from before the update and have everything inside.
In the old files section of the game, it says i may still have a copy of the original save file.