Every page returns a 500 error except home page and admin panel

1) Try turning on debugging — enable wp_debug and wp_debug_log and look in wp_content/debug.log

see https://codex.www.ads-software.com/WP_DEBUG

2) Check your server’s error log.

I don’t see any 500 errors but you do have problems.
https://sitecheck.sucuri.net/results/www.stop-calling-me.org

Your navigation is looks wrong but seems to work.

The site is now completely down and I don’t know why.

I have got debugging set to true, but no debug.log is in wp_content.

I’ve hit a brick wall.

Ask your host if they see any reason for the 500 error.

wp-content/debug.log is where the debugging content would go

check the server’s error.log file.

Got a ticket open now as they said they can’t find any reason.

I was able to set them up an admin login before it all went fubar too, but it’s no good if they can’t access the admin panel.

Got a ticket open now as they said they can’t find any reason.

nonsense. 500 errors are logged. Have you looked in your hosting (not WP) control panel?

I can access logs but they are gibberish.

Gibberish means you don’t understand them, not that they’re useless. Copy the last 50 or so lines into pastebin.com and paste a link to that page here.