I applaude your commitment, but allow me to give this a different angle of perspective. Cutting out things from your life that you love will just make you sad, bored, or resentful at your new arrangements. That's going to make it a lot easier to relapse.
Keep doing what you love. Even eating. /r/Fitness is going to hate me for that one, but yeah I said it. Enjoy life while you cut that weight- just enjoy it in moderation.
Don't sit in front of the computer (or T.V., or anything for that matter) for more than an hour without getting up and moving around for at least one or two minutes. Studies show that remaining completely sedentry slows down your metabolism, along with other nasty effects. Look it up if you like, but the bottom line is it won't help your weight loss.
In my own experience, loading screens are a hidden blessing. Yes, I'm looking at you League of Legends. Subscribe to /r/bodyweightfitness and find out what excersies you are capable of doing, and do a few of them while you wait.
If you know you're going to be sedentry for some time, owe it to yourself to do something active to balance it out. Go for a walk after gaming for a while. Jog if you can handle it. Get a Pull Up Bar from Crappy Tire and haul ass.