Do you mean an online gaming addiction, or an internet addiction as a whole? Because people use the internet far more than they think they do, haha. The internet's pretty huge, so I don't really know if it's possible to say you're addicted to the internet.
As for me, my advice would be to find new hobbies that you think you'll enjoy. Instead doing that one thing all day every day, you've suddenly got three, and you can devote your time equally (and maybe break out of your old habits in the process).
This stuff's purely theoretical, by the way. I don't have any experiences with addiction, I don't think. Though if I had to give one example, I'd say I'm way into cookery, haha. I love to cook, learn about ingredients and combinations, getting people to criticize my food, yada yada. But it's not like I'm not addicted or anything, you know!