@yiannis1991
Did you recently registered this domain? I get This domain is registered at Namecheap. This domain was recently registered at Namecheap. Please check back later!” When I tried to access your site from Canada.
If the domain is recently registered, may be you need to wait about 24 hours for the DNS to get resolved in servers. This could also happen if you recently changed your DNS settings such as changing to Cloudflare.
If you are using Cloudflare, make sure their server name information is correctly entered.
If you have access to a control panel like cPanel, check that the files in the WP install is there not deleted.
You can contact your hosting provider for help on this because your entire site is down and they may be able to fix it sooner than any of us. I have taken down my websites by messing around in .htaccess files. Hosting provider support teams always helped me fix these issues. It should not be a problem for them.
All the best.