I wonder if it would be worth your while to either re-import your account from Time Machine or try migrating it from another source?

Maybe a bad install is preventing the deletion of that account because macOS thinks it's your only admin account. (Have you tried deleting it while logged in to a test admin account?)

Last edited by artie505; 08/18/17 02:00 PM. Reason: Expand
The new Great Equalizer is the SEND button.

In Memory of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire