Sounds like you performed the basic first steps of troubleshooting issues such as this. Next thought would be to check your internet connection - if you're using WiFi and have you're own router - try rebooting the router - easiest way is to simply unplug it, wait a minute and power it back on. Also check you're connection speeds to verify that you are connecting at the speed you're paying for - for example, this site has various tools depending on what hardware you have.
