No able to login with hide backend enabled

I just set up iThemes Security on my clients site and enabled the hidden backend feature among other settings. I changed the salt as well. After I did this, I was able to log in and out a few times. I notice an error notice in my admin and after looking it up, my theme developer offered advice on how to remove the hook.

I then changed a line in my wp-config.php:

From this: define( ‘DISALLOW_FILE_EDIT’, true );
To this: define( ‘DISALLOW_FILE_EDIT’, false );

I left for an hour or two then came back. Now I am able to access the login page, but when I try and login nothing happens (regardless of both my active logins). No errors, nothing just not logging me in, its staying on the page after a refresh.

I changed the line in wp-config.php back to see if it helps, and it will won’t work. In the wp-config.php I turned on error reporting and these are the errors that are showing:

ERROR: Cookies are blocked due to unexpected output. For help, please see this documentation or try the support forums.

and on top of the page I have these PHP errors as well: WordPress database error: [The MySQL server is running with the –read-only option so it cannot execute this statement]
INSERT INTO wp_options (option_name, option_value, autoload) VALUES (‘_transient_doing_cron’, ‘1516303950.3731660842895507812500’, ‘yes’) ON DUPLICATE KEY UPDATE option_name = VALUES(option_name), option_value = VALUES(option_value), autoload = VALUES(autoload)

Warning: Cannot modify header information – headers already sent by (output started at /myroot/wp-includes/wp-db.php:1399) in /myroot/wp-content/plugins/better-wp-security/core/modules/hide-backend/class-itsec-hide-backend.php on line 375

Warning: Cannot modify header information – headers already sent by (output started at /myroot/wp-includes/wp-db.php:1399) in /myroot/wp-login.php on line 421

Warning: Cannot modify header information – headers already sent by (output started at /myroot/wp-includes/wp-db.php:1399) in /myroot/wp-login.php on line 434

Warning: Cannot modify header information – headers already sent by (output started at /myroot/wp-includes/wp-db.php:1399) in /myroot/wp-includes/pluggable.php on line 920

Warning: Cannot modify header information – headers already sent by (output started at /myroot/wp-includes/wp-db.php:1399) in /myroot/wp-includes/pluggable.php on line 921

Warning: Cannot modify header information – headers already sent by (output started at /myroot/wp-includes/wp-db.php:1399) in /myroot/wp-includes/pluggable.php on line 922

Any suggestions? I have to get this fixed ASAP as I have a meeting in the morning with the company. Ouch!!