ITunes was unable to load data class information from Sync Services. Reconnect or try again later AND Your iPhone has never been backed up to this computer AND always Not Responding

Question

First: I get the message telling me that "iTunes was unable to load data class information from Sync Services.  Reconnect or try again later."
Second: In the Summary Tab under Backups, iTunes is telling me that my iPhone has never been backed up to my computer - which is not true. It's also telling me that my iPhone has never been backed up to iCloud. Again, not true. Although my backups are all missing from iTunes, I can see what I think is them in their folder: C:\Users\*your user name here*\AppData\Roaming\Apple Computer\MobileSync.
Third: iTunes is SLOOOOOOOOW. It takes nearly ten minutes - sometimes more - to launch, and when it does, it's constantly not responding. It seems every time I touch something it stops responding.
Fourth: I've been searching this "help" forum for a solution, and I've seen many other references, yet the only suggestion I've seen from someone from Apple is a reference to a solution that is over 2 years old - and DOESN'T WORK for anyone I can see who's tried it!
I've tried everything I could think of, and that others have suggested, including:
Uninstalling and re-installing iTunes
Ensuring I have the latest version of iTunes
Re-setting sync history
Renaming my Backup folder at the path above, and letting iTunes create a new one
Running around the house whilst pulling my hair and yelling obscenities
None helped. At all.
Hmmm... Been a devoted Apple/iOS guy for years, but maybe it's time to switch to Android?

Answer 1

I've resolved the issue with iTunes constantly not responding. It's a bit embarrassing. I had a DVD in the drive that was corrupt, and once I was able to remove it - BAM - iTunes ran perfectly.
I'm still getting the Sync Services message, and my backups are still not showing in iTunes.
Getting there.... I hope!