Are you trying to watch the videos in a definition that is higher than SD? If so, try turning off, or pausing, the Video Data Saver, which you can do in the Video Settings of the HughesNet Usage Meter or by signing into the HughesNet MyAccount site and clicking on the Settings tab. This may help with the buffering.
I see it's your first post here, so welcome to the community! I suggest checking out Gabe's suggestions. In addition, I'd also try disconnecting your DirecTV from your network if you're not using it. It will constantly download and use your data, and if you are out of your monthly data allowance, you will have reduced speeds per our Fair Access Policy.
It's been a while since we last heard from you, so we will close this thread. If you still have concerns, please start a new thread and include a detailed explanation so we can more effectively help you.