Google Cloud - 503 Service Unavailable on WHM / CentOS 7

Job ID: 35220012

Budget: $25 – $50 AUD

NOTE: This MUST be done via remote desktop with my assistance from my computer, as I CANNOT share access.

I was clearing out unused space via terminal in CentOS, and now I am faced with a 503 error when accessing cPanel (2083) "503 Service Unavailable The server is temporarily busy, try again later!"

On port 2087, I just get "ERR_CONNECTION_REFUSED".

I have done some Googling, and people say it's firewall related. I can't find a way to resolve it; either way, I cannot get into WHM or cPanel, but the front end and websites seem to be working fine.

I can only access it via SSH in Google Cloud at the moment.