Type in a domain name, and the site will let you know is the site is down for everyone, or if it's just you. If it winds up being just you, grab a staff member on chat, or email support with your IP address so that we can check our firewall and see if you set it off and got yourself blocked, which is usually the most likely scenario when it winds up being "just you". Don't know how to figure out what your IP address is?
will tell you your IP address - we need your computer's IP when those things happen, not the IP of your web site. We already know the IP of your web site. :)