Lost files while trying to back up documents into iCloud

Last night I tried to back up all my files from my Mac as I want to buy a new Mac. It was taking hours and hours so I tried to stop iCloud from backing up. I think I did this:

1. In "System Preference" I clicked the little apple ID icon
2. Then in "Apps on this Mac using iCloud" I unticked "Desk top and Documents" and "Optimise mac storage" (I don't think it had finished backing up my files)
3. This bought up a warning that my documents will no longer be on the desktop but in the cloud.
4. I thought this was OK and that any documents not yet in the cloud would stay on my computer.
5. BUT all my files and folders on my computer are gone and a lot of folders and files are not in the cloud either.
6. On my computer I re-ticked "Desk top and Documents" (made sure all the boxes were ticked in the "Options" box next to it and re-ticked "Optimise mac storage" But still there are no files or document on my computer.

HELP!!