Everything disappeared

You could also try opening one of the Premiere Pro Auto-save projects, maybe that way you can recover some of what you worked on.

It seems to me that you should describe exactly what your procedure was because, normally when this happens it is usually "human error". As far as I know Premiere Pro does not have the privilege to delete edits or clips, that is done manually by the video editor. Could it be that you were saving in a cloud? on an external drive? on an SD memory card? If you know any details you should tell us so we can try to figure out what could have happened.