It seems that you have disabled regular logins, so currently there is no way for you to access the authenticated section without using a GMail address.
To fix this, you will need to change the value of 3rd_party_allow_regular in the wp_options table to 1 through phpMyAdmin or by using SQL.
To avoid this in future, be sure to check the box next to “Allow regular logins as well as email/google logins?”.
