Died and Terrain Changes

While i was playing on a dropper map that I had made for mcpe on survival I dropped and died then respawned in the bedrock level after I respawned the second time in the ocean of a world that had only two little islands. The world I had before all of this was a Mesa world of clay. I know it might be late to get my stuff and terrain back but I hope this helps stop it happening to anyone else😃