Somehow I completely lost access to my mysql installation. It would not run because of a socket problem. I worked for over a week to try to regain access but the only thing that made it work again was removing mysql and all the mysql files and reinstalling. I could not log into WordPress to export so I backed up the /var/log/mysql/wordpress and then deleted everything. I should have backed up the whole /var/log/mysql directory because I could not restore from just the wordpress files. Lesson learned.
Fortunately I was able to reexport the old WordPress.com entries to my local rPi version. Then I rescued my first new post from a google.com cache. But I lost the long post from March about my motivation for starting this rpi WordPress site in the first place.
This prompts my new motivation to research and develop a backup plan.