You have zero databases in your cpanel account. After login to your cpanel, you can see the mysql database consuming more disk space. This can be corrected by the following steps.
Login to server and edit cpanel.config.
[root@server /]# vi /var/cpanel/users/cpanel.config
Replace 'disk_usage_include_sqldbs=0' with 'disk_usage_include_sqldbs=1'
Save this file and run the command given below.
[root@server /]# /scripts/update_db_cache
In the whm-tweak setting, you need to enable the option
'Use INFORMATION_SCHEMA to acquire MySQL disk usage (MySQL 5+ required) '