Folders intact, but all are Empty

Please help me uncover a mysterious and possibly retrieve a bit of my life back.

Every single one of my iCloud folders--which are my life--one day appeared EMPTY. None a single folder is missing, however, all of its content is completely gone. This is as if a hungry elf came along, jump inside each one of my many folders and eat up each one of the files inside each folder.

My iCloud plan is at 200GB.

I use three devices for this single iCloud. Mac desktop (2022), MacBook Pro (early 2015), iPhone--in this order meaning I mainly work on my Mac desktop but always accessing my files from my iCloud storage via my finder> iCloud .

I do not use my HD for file management. My whole life--all my files, the ones that were once inside of all these folders, is stored using iCloud > iCloud Drive when I am opening and saving files.

I sign in to iCloud. I sign out. And still. All folders are empty.

The one bit of activity that may help the Community help me solve this mystery is this: Over a month ago, my MacBook stopped work in what appeared to be a bug. I had to reinstall the MacOS system. Since my MacBook is an early 2015 model it no longer allowed me to install whatever newer OS system it had before it got a bug (which really means it froze up on me and I had to start it up in Recovery.

After hitting a wall, I eventually took it in to a local authorized dealer and they were able to install OSMonterey. The dealer asked if there was anything important on my Macbook--since ALL my file son the iCloud drive, I said no. And they are. When I teach on campus I access my Keynotes via iCloud.com. Nothing is stored on the HD of any of my devices.

Other than the above actions, I have not gone into my iCloud eating up all my files inside each one of my folders. Would this have something to do with TimeMachine on my old school MacBook? That is, when the dealer erased my MacBook did this do something to my TimeMachine (which I do not remember setting up to connect to my iCloud drive) ?

I am a college instructor and small business owner and as with all of us in this community, my files are quite important. Please help me.

Kindly,

MariSela