I'm not sure what you mean with "Drained all my bandwith". In case you are on a metered internet connection this could be an issue indeed but if you have unlimited access this shouldn't be.

WCG will consume around 250MB per day unless you have a PC with a lot of cores. I can imagine that for the start-up it will consume a bit more to load all information but then it will be around 250MB spread over 24h