Robert,
Do you use One Drive ?
Do you have a folder like:
C:\Users\rober\OneDrive
Does it perhaps have subfolders like "Documents" and "Pictures", etc.
If so, what's inside those folders?
That's what I wanted to say. Unfortunately, Robert is missing 220 GB - & OneDrive only holds 5 GB unless more was purchased. (Can it be MSFT gave him the extra real estate & plans to send him a bill?) But maybe the upgrade did the following automatically.
Before my upgrade to 1809 (still in 1803) - I had set Desktop, Pictures, & Documents to go to OneDrive. That's at "OneDrive Settings, Auto Save tab, Update folders button". That moved the contents of those folders from C:\Users<Username> to corresponding folders in C:\Users<Username>\OneDrive. The C:\Users<Username> folders remain, but are empty. Any content previously in any of the OneDrive folders also remained, was not wiped out.