All Files Are Gone

I accidentally changed the permission of wp-config and now all of my files are gone. And when i say all, I mean everything. This error pops up on my cPanel: Failed to save cache file 
And this to my website:ForbiddenYou don't have permission to access / on this server.
Server unable to read htaccess file, denying access to be safeAdditionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.

How do I fix this? Thank you.