everything is moved

I logged out of my world and when I logged back in the chunks had moved all randomly.

I was in the process of building a particularly massive kingdom at the time and I use the word massive without exaggeration especially in a survival world without cheats. So logging in to find my world in disarray with villages being split up and moved around my project in pieces scattered across the seen distance and biomes splitting up and having reformed with chunks of each other in the other. I have a plethora of hours invested and I would be very frustrated if I have to start from scratch on a fresh world as the state of the one I have created is well, to put it mildly, ruined.  Please Help I have no interest in playing until I know for certain that this can't be fixed and I have to resign myself to starting fresh and trying to find another ideal location for my grandiose building plans.