First things first:
What modem do you have ? (HN9000 or HT1000/1100)
What plan level do you have ?
Check the modems SCC at 192.168.0.1 to see if you are in FAP or have an active error code.
Then once that info is known (it tells us how much "horsepower" you have) then we can look at streaming sources, streaming rates and speed tests.