If your internet service provider has a cap on bandwidth, make sure you set bandwidth controls to limit your your usage while streaming.
To find your bandwidth controls, navigate to your Settings.
Now choose Connection.
On this page, you have the option to select your preferred mb/s, megabits per second. This may directly impact your video quality while streaming. Select one of ur available options and then return to your stream. Your settings will automatically take effect.
If you are curious what your current streaming speed is, you can choose to have it displayed while you are streaming video.