PDF files disappeared after Tahoe upgrade

Most all of my scanned/saved pdf files (from at least 10 years) disappeared after Tahoe upgrade, folders on iCloud and on my MacBook are empty! This is a major problem for me. I I have had Mac's for eons, and this has never happened before. I've always assumed iCloud was my backup, WRONG! Guess I need to purchase a dumb plug in SSD to backup to time machine...

Am I the only unlucky one this has happened to?