Fatal GUI DB Error

My freepbx system is still running and phones still work, but when I attempt to connect to my GUI I get the following error:
DB Error: connect failed
Trace Back
/var/www/html/admin/libraries/db_connect.php:63 die_freepbx()
[0]: DB Error: connect

/etc/freepbx.conf:9 require_once()
[0]: /var/www/html/admin/bootstrap.php

/var/www/html/index.php:18 include_once()
[0]: /etc/freepbx.conf

Any help to return my GUI and fix would be appreciated. Also need to delete old backup files and not sure where I need to go to remove all those backups. Using hard disk space.

I can only access shell command so any assistance would be great.