Hello missdahlia87 Welcome to the Seven Forums!
Surprizingly this is usually a quick fix by one of a few methods since the problem is far more common then most realize. The first thing any ISP(Internet Service Provider) will advise is simply unplugging the cable modem for a good 20 seconds or so while the desktop or laptop is shut down. Often the further advixe when hard wired would be unplugging the ethernet cable as well.
A simple restart may get you right back online while at times the Ipconfig /release and Ipconfig /new commands entered at the command can be a help in resetting and re-establishing a private IP address again once the modem resyncs with the ISP.
Your configuration is the same as always to note here however while the time out factor to reach your home page isn't being met. Sometimes clearing out the IE or other browser's offline content being the cache and temporary internet files as well as looking over the advanced IE settings to see if the automatic network discovery box is checked off can also help.
With anything misconfigured and then suddenly configured correctly or when the connection is restored you may see the prompt screen for selecting Home, Work, or Publc appear where you simply click on the Home option to get back underway again. As far as Comcast being slow at times the particular time of day or night can play a role as far as how populated the host servers are by internet traffic.
Don't you love the promises of faster speeds and then run into slllowwwww... downs?!
With a recent account change here to the business class Comcast has been promoting lately I still am yet to see any great speed increases overall.