Really Simple SSL

I’m having issues with that plugin, it has taken down my whole site.

Hi @embray23,

You probably didn’t have a valid SSL certificate, which is required for the plugin to work.

To deactivate it, you can use the deactivation link in the plugins overview, or use the force deactivate method:
https://really-simple-ssl.com/knowledge-base/uninstall-websitebackend-not-accessible/

Your webhoster can install a valid SSL certificate for you. As soon as the test on https://ssllabs.com/ssltest returns an A, you can activate Really Simple SSL again.