You need to find something else that you take pleasure from. Ideally, something that is productive, but anything that is less harmful to your real life than gaming is good.
You are already on the right track by realizing that you have an addiction. We all know how the addiction works, whenever you are faced with the prospect of real life responsibility, your mind immediately looks to gaming because it is an easy distraction. The next time you feel the computer calling you, think about how you feel after hours of gaming. If you are anything like me, you feel almost guilty for wasting so much time. Then you need to think about how you feel after you accomplish something worthwhile. If you are anything like me, you feel good because you know you did something meaningful. After thinking about it like that, you probably wont be so enthusiastic to game.
You arent hopeless, you recognize your problem, and you have the power to get your life on track.