Screwed up administrative name on sudo when trying to change usernames
Reboot into Single User mode
Run /sbin/fsck -fy
Run /sbin/mount -uw /
Run vi /etc/sudoers (assuming you know vi, otherwise use nano)
In the "User privilege specification" part replace %awesomechris with %admin (the % is important)
Save and reboot


PS: The % identicates a user group, so creating a new user didn't help (even if you would have named it awesomechris instead of username)

PPS: Once everything is fixed, remove Admin rights from users who don't need it (make sure at least one is left). Then log in with an admin user, run sudo WHATEVER-IS-NEEDED-TO-REMOVE-YOUR-SOFTWARE and enter the password of the same admin user to confirm).