If you're not currently out of plan data, and if both boxes at the top of this modem page are green, the first step in troubleshooting your speed issue will be running some speed tests. The instructions for the speed tests are here. Please be sure to read the instructions thoroughly before running the tests in order to ensure they're run properly, and after you've run a few please post your testmy.net "My Results" page URL into a reply so that the test results can be viewed.
The HughesNet reps are on M-F from approximately 9AM to 6PM EST. They will be the ones to help you with your speed issue, but they will need some speed test results to be able to do so.