So your homepage is showing "Unable To Connect Database"? That means that the WordPress server has crashed before due to heavy loading. It is also a sign that you should start considering to upgrade the VM to a bigger one.

The Cause

Usually is due to heavy traffic (the server can't handle too many traffic with the current VM configurations). Now it could be due to many visitors coming to your site, too many robot crawling your site, and/or a service denial attack (DDoS). In this case, you'll need to analyse the CloudFlare traffic chart and your VM's CPU performance to root cause the problem.

How To Upgrade

You should consider upgrading your VM with a better vCPU selection. Visit this page after you bring the WordPress server back to life.