Backstory
I live in a family of 7. We are a very tight-knit family, all living under the same roof, and we love each other dearly; but we have very strict rules about a lot of things, the one in this case being video games. Now, my father and older sister love playing video games. My father plays games on his off-days, and my older sister (who I will call Laura), who graduated college, also plays games. My older brother (Ras) and I used to play a lot of online games together, slowly building up a kind of "gamer duo", if you will, for the past 3 or 4 years. He's a freshman in college, and I'm a high school senior.
The Problem
We were told before that we can start playing games after college. A lot of you might be thinking, "Well, gee, just wait until after college and then play all you want." Unfortunately, it isn't that simple. Laura used to play games in community college (which she got in trouble for), then went on a bit of a gaming spree when she transferred to the university. Then, she always used to talk to us about the games she played, how much she loved it. I believe that that has subtly affected me and Ras, on top of the fact that she got to play earlier than when she should have, and the fact that she still plays games. Ras and I very alike, and are both addicted to a certain game at the moment (we both play the same online game, and often form up into teams), and Ras has told me that part of the reason for the addiction is a lot of stress at home, and he says Laura being around tempts him to play games. We have often got in trouble for playing games when we shouldn't have, and ended up getting suspended from privileges. What would be the steps to curbing this addiction, if it is possible? Are there any coping methods to help?
EDIT: We do not watch television or movies, and don't have any friends outside of the immediate family (we don't know our extended family). Entertainment comes mostly in the forms of writing, drawing, reading, and playing board games.
EDIT 2: Playing games has often taken up more of Ras' time than my own, and he would often stay up until 0200-0400 in the morning playing games. Throughout the day, we don't do much else besides playing games: exercise is pretty much non-existent, and chores are non-existent; we do take at least a shower a day, but sometimes forgo brushing our teeth. During meals, if we do actually sit down to eat, we would play some quick 2-player game or watch a video while we eat, then return back to whatever games we were playing before the meal. Ras even takes his laptop to the bathroom when he goes.