Deleted Plugin Files, Can’t Access Plugins Page in Dashboard

This plugin has really caused issues with our site. Upon installation and activation, we could no longer access the admin panel. We would enter our login info and it would then take us right back to a blank login screen. I see now that we should have checked off the option about not showing cached pages to logged in users, but unfortunately we were no longer able to access our dashboard to make the change.

I finally resorted to logging into our back end via cPanel, deleting all of the plugin files, and modifying our .htaccess file to remove all traces of “WP Fastest Cache.”

Now, we can log in and access the admin panel, but when I click on the “Plugins” page in the dashboard, it takes me back to a blank login screen. It’s as though some portion of the plugin is still active somewhere.

How do I completely purge this thing from our site?

The page I need help with: [log in to see the link]