Error 522 just started happening when I hadn't changed anything on the site in a couple of weeks

522s are covered at Community Tip - Fixing Error 522: Connection timed out

But what do you mean by that?

Cloudflare can’t secure your website, if you mean SSL.

If your site is hosted on the machine where I think it is, then you have an expired certificate and should fix this as soon as possible as that leaves your site insecure.