Long story short I had someone hack my admin account. They got into the boards email account somehow, and the first thing I did was change the password for that email account. I then used the 'forgot password' feature of xenforo to try to get my account access back, but never received the email......because the board can't send emails since I changed the password for the email account! Woops, should've done that the other way around....
I still have access to the actual server, so I'm hoping there is a SQL command to change the password used for the boards email. I'm using Gmail.
If you have access to the server, just register a new account - note down the account ID - and then remote/FTP to the server and add the new account ID to the superuser ID list in your XF config.php file.
You should then be able to login to the ACP with the new account and perform whatever changes are necessary to get things back to normal.