Hello,

It looks like there was a spike in your traffic which caused the sudden CPU load. What I could suggest is:

• Make sure to add enough resources to your Droplet, you could run a stress test in order to be able to determine how many visitors your site could handle at once:
  https://www.digitalocean.com/community/tutorials/an-introduction-to-load-testing

• Also make sure to optimize your Wordpress website, for example, delete all plugins that are not absolutely necessary, install a caching plugin and maybe enable a CDN

*Check your logs and make sure that there was no malicious traffic towards your site, you could, for example, use this script here to summarize your access logs.

Also, it sounds like that your Apache service might not be running, here are some steps that you could follow on how to troubleshoot common Apache problems:

https://www.digitalocean.com/community/questions/how-to-troubleshoot-common-apache-issues-on-linux-server

Regards,
Bobby