World utterly destroyed by corruption

I have had a survival world for 14 months, playing nearly every day. Today I log in, and it immediately closes the world and says possible corruption. I knew something was up when I logged in again and read that my Horse fell out of the world. Anyway, I look around and a whole strip of the world is reset back to its original state, and other chunks absolutely deleted, just holes of the void. I know this can't be reversed, so I'm at least bringing light to it so it can be fixed before others have their worlds destroyed.