Lightroom gallery. All albums gone

The first thing that always comes to mind in cases like this is, are you signed in with the Adobe ID under which you have your subscription active? If you got signed out, or if you signed in under a different ID, you would not see any of your prior work.

If this is not the case, please tell us more about your system (PC, Mac, iOS, Android, what OS and version), and what version of Lightroom you are using, etc.