First, we encountered the error stating we had used up all our space (2gb for Switch) and needed to make room by deleting something before we could continue to play Minecraft.  We decided to move our primary world of ~170MB to a realm - it seemed a perfect solution as we invested SO much time into it and wanted to create more safety/redundancy by moving it to a cloud server.  We clicked "play as realm" in our switch and proceeded to go through the process of paying for the realm.  After returning to the select world screen, our 170Mb world showed as 0.03Mb, and we still had 0 minecoins and no realm?!?!  Our world seems to be completely GONE, or otherwise reset to the original seed at first-spawn.  This seems like an incredibly MAJOR bug.  How can this even happen?

I reached out to support to find out how we might recover our world (minecraft support request 1054367), and they offered no help and suggested we report the bug.  You can see in the screen shot that the image (circled on the left) of our 0.03mb world is from the time the world was current and at ~170Mb.  I am not sure I can enjoy playing minecraft again until we understand what happened here and can recover our world.  It must exist somewhere, right?  How could it have been deleted following this process?

Thank you so much for your help!  We don't even know if we should go to Mojang, Microsoft, or Nintendo for help with his.  This bug has caused devastation in our home.