in case your site or your cpanel seems to be down,the probable cause is that you been blocked by the server firewall, this can happen because you used a wrong password, for email, cpanel or even login to the admin area of your site.
All our servers have firewall and they protect your site from hackers. It may also happen that while editing a site you are blocked, this could be the cause of a vulnerability on your script and the firewall assumes you doing something dangerous. You will be blocked.
Every one else can you see your site but you cannot because the firewall (ours, the one on the server ) is blocking you.
you can unblock yourself, login to the customer dashboard, and then under "support" click Unblock IP
you can unblock yourself,
if this happens repeatedly and it is not the passwords, then it is the script. Unblock yourself first then go to cpanel and disable Mod Security. After your edit the site, login to cpanel again and enable the modsecurity once more, it is very important as it is one of the first layers of protection against attacks from hackers.
If you have any problem contact support.