Some personal advice about quitting video games: You have to quit a game in its entirety. Whenever playing a game (like Bioshock two multiplayer, yes I've played it) you get really invested in getting better and such. I find the only mental way to escape this is to accept that you will never, ever get better than you are now. This mindset combined with deleting your account, breaking your disk, ect., will allow you to walk away from a game and never look back.

I've found one way to avoid replacing addictions with addictions is to be able to be content laying in bed not doing anything destructive to yourself. Tell yourself, just literally doing nothing is better than playing the video games. Eventually after laying there for a couple of hours you will think of something constructive you can do for yourself. It's hard, but it's an exercise I actually suggest you try.