My world is gone!

I have a flat world on my Minecraft Pocket Edition called Craftopia that I've had since 0.9.0, and I was working on a Burj Khalifa replica, but when I came back to work on it after the 1.2.10 update, MY ENTIRE WORLD WAS GONE! So now I have 2.5 years of hard work gone down the toilet with this world, so you have to work on a way to get it back. And if Mojang/Minecraft can restore this glitch, well then I guess nothing can, and I'll probably be depressed for all eternity. Oh, and also, I just switched from an iPad Air 2 to an iPad Pro, so maybe I need to switch this world over from my Air to my Pro.