Hi Dharlequin. I'm Greg, 10 years awarded Windows MVP, specializing in Installation, Performance, Troubleshooting and Activation, here to help you.
They are apparently keeping Google Backup as I still have it and wasn't moved to Drive for Desktop. I also see here that there's still both:
Compare Backup and Sync & Google Drive for desktop - Google Drive Help
I would see if you can System Restore to a point before you started this as it may be the only way to undo the registry hacking and all else you've done: How to use System Restore on Windows 10 | Windows Central
Then start over to install Drive for Desktop from here:
Install and set up Google Drive for desktop - Google Workspace Learning Center
Keep me posted on your progress as I will be here to help until the case is resolved.