|A proxy can't help in that situation, because all the traffic must run through the ISP first.|
So if you have reached the limit of 3 GBytes and can't buy a higher limit, you still have to wait until next month.
Every video on YouTube, depending on the quality, may have several hundret megabytes.
Doesn't matter whether you store the video to your machine, even watching the video is also a download.
The original poster should always write the last response !!!
Let us know, if the problem is solved !!!