Restore Offline Website Urgently

My whole site, komete.io, has suddenly gone down and I need it back up as quickly as possible. I can log in to the hosting control panel and the server via SSH, but I’m not sure if any recent code or configuration change triggered the problem... (Budget: €8 - €30 EUR, Jobs: DNS, Linux, PHP, Server, Troubleshooting, Web Hosting, Web Security, WordPress)