How long the data lasted in the first month vs the second month was explained in the following reply to your post in the other thread (which you replied to)...
As well, streaming is a very data intensive activity. Going by Netflix's numbers, it uses about 3GB per hour in HD, 700MB per hour in SD and 350MB per hour in LD. So, with a 10GB plan, that's just over three hours of HD streaming, just over 14 hours of SD streaming, and just over 28 hours of LD streaming. And that's only the streaming. Anything else that uses your HughesNet service will use data, as well. Streaming via your Hopper could use more or less data.
Additionally, HughesNet recommends against connecting a satellite TV receiver, as those receivers can use data for more than just On Demand viewing (streaming), and there's no way to control it. This likely also contributed to your data usage. It's recommended that you disconnect your Hopper from HughesNet for that reason.
A link to some data saving tips was given in the other thread.
People on Internet service that has plan limits before being throttled really need to educate themselves on how much data things use, especially video streaming. Really not much different than monitoring a cell phone data plan.
Knowing how much things use would flag in a person's mind that something is going on for the first 20 days of new service when use resets each day.