Help Me Stop iCloud Sync in Mac OS Sierra!
I upgraded to macOS Sierra 2 days ago. During the installation process, I selected "Use iCloud Drive" since i had been using it with El Capitan on my MacBook Pro. The installation completed, and I started opening my apps to see what had broken in the install process. I also decided that I did NOT want to use the new Sierra feature that synced documents to iCloud and removed older ones to save space. I opened System Preferences and deselected Optimize Mac Storage in the iCloud preferences, but I DID check the Documents and Desktop setting in the same pane. I closed the preferences and started working on something else, but when I returned to the desktop later, I discovered that EVERYTHING I had on the desktop had disappeared! I opened my iCloud Drive icon and, sure enough, the Desktop folder shows with a cloud next to it. I next received a warning from Box Sync that my Box folder had disappeared and needed to be relinked. I opened the folder and ALL the files inside of it were gone. I immediately went to System Preferences and de-selected the Documents and Desktop option, hoping things would return. They did not. Now, iCould Drive is trying to upload files to the cloud (which there is enough room to do in the cloud) but it won't stop the sync. It has moved 1 of 99 Gb of data at a very slow rate. Now, when I go to System Preferences to open iCloud and turn sync off, System Preferences hangs and I have to force-quit the program. I open the iCloud Drive folder and a spinning sync shows in the lower right corner but it apparently never connects.
What do I have to do to stop the iCloud sync, pull the files it has uploaded back to my Mac, and fix my System Preferences pane so I can open iCloud preferences again?
MacBook Pro, macOS Sierra (10.12), 16 Gb RAM, 1 Tb hard drive