Database Error

I just installed Wordfence at my host’s suggestion. After installation, I tried taking the TOUR, and included my email address where asked. I got a message saying that an API key was not found, and that I could go to the OPTIONS page and SAVE CHANGES to force it to give me a new key.

At the same time I tried to configure my Firewall Rules, but each time I tried to SAVE CHANGES, nothing was saved.

The third time I got an “Error establishing a database connection” message and the site will not load.

In the past I have changed the name of broken plugins thru FTP to keep them from loading, but this didn’t work with Wordfence.

HELP please…

https://wordpress.org/plugins/wordfence/