This is rather embarrassing. I was trying to clean up the options database using the "clean-options" plugin but looks like I went a wee bit too far.
When I tried to login to wordpress this morning, the login screen "shook". There wasn't an incorrect pw or username message - just the shaking and prompting again for username and pass. Oh, and the Google Authenticator thing (as I had installed that plugin).
I still have full FTP access, so first thing I did was to see if I had messed up authenticator - FTP'd in and deleted it. No longer prompts for an Authenticator number. Tried logging in again with existing - no dice.
OK so tried the "lost password" link. Interestingly enough, when I entered in my username, it "shook" again - presumably did not recognize the username. But when I entered in my e-mail address, it dutifully sent off a password reset link. Using the link, I tried to reset my password. That seemed to work - I entered in a new password twic, and it prompted me to login again. I tried again with the new password, but again it didn't work - just shook again.
Just in case I messed up something with the password reset, I tried again and got the same result.
I suspect I've messed something up with the username but am not sure. It is clear to me that I have certainly messed something up with my overzealous deletions in the options table.
Does anyone have any suggestions as to how I could fix this? I do have full FTP access. I don't currently have access to the database as my work blocks ports which phpMyAdmin uses. My preference would be to try to fix this if it is possible. Any suggestions anyone might have would be most appreciated.
And apologies in advance - this was admittedly a rather boneheaded move on my part.