Hi Don, 
Sorry to hear of your problems.
That´s what I always was a bit afraid of as well.
Never tried an in-place-upgrade so far. 
To avoid such a scenario I always do a fresh-/clean-install, so basically a nuke-and-pave-approach.
With 3 partitions (home, root and data-partition) I just keep my data-partition (not formatting) and install a fresh root and home.
Actually there´s just a lively discussion going on about how it can be done here: General question regarding support period of distros (Ubuntu and derivatives) .
All the best and many greetings.
Rosika 