I tried all the suggestions but nothing worked. Then I tried starting the UsoSvc service several times but kept getting an error 87. You can look it up in your system event log.
After more searching, I came across an article in tenforums that suggested restoring an original version of the registry key for this service. I was skeptical but I tried it. I went into safe mode and modified the registry key. After a reboot, I went into Windows Update in settings and it all came back!
I thought it might have been corrupted OS files, but when I did the DISM check they were all good so I was baffled. In my case, it turned out to be a corrupted UsoSvc registry key. When I put it back to a pristine state the Windows Update screen worked again.
I hope this helps someone out there.