One Drive coopted My PC folders upon sharing Microsoft 365 on old device to my new one even with OneDrive uninstalled from both! Fixes?

All files I had created or amended since the extending Microsoft 365 to the new Dell were apparently lost.  After 4 days trying all recovery tips offered, ChatGPT assisted me to reinstall OneDrive in C: and constrain it somewhat.  I was able to uncover all files from a  a OneDrive folder "/Pictures" including my Word documents and my entire local /Pcitures folder.  I am still trying to unscramble OneDrive Control, e.g., my share icon moves all files I am working on to a OneDrive folder and defaults to that pathway when I use Save As.  This has been nightmare!  How do I get OneDrive claws completely off my computers.