Ensure that caps lock is off, and that you are completely sure what your cPanel password is. If too many failed login attempts are made, you will be locked out of the system for 10 minutes. If you try to login during the 10 minute lockout period, the lockout will be extended.
If you cannot remember your cPanel password, it can be reset from the client area or by contacting technical or sales support.
It may be that your IP is probably being blocked by the
server firewall, 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,