I like computer games as much as the next guy but getting out of your 7+ hour routine of games is the right decision, there is so much more to life. I don't know how long you've played games or for how long you've been playing them at that rate but don't be surprised to feel like something is missing. Get outside, exercise, meet up with friends, read a book AND play the odd computer game, I don't want to go too far down the line of comparisons with drugs but going 'cold turkey' isn't needed to be honest. Your choice of course but to go from 7 hours to 0 will have an effect. You simply need to organise your time better and not allow the games to take over your life, balance is everything.
A few things though, rather than just a simple hobby, something that actually fills the void of self achievement or self worth (creating something for example) might be an idea, playing games involves solving tasks, doing things, achieving things, breaking records, you need to find something that appeals to this side of yourself as much as anything else. Also, exercise really is a great thing, it helps us in so many ways it's untrue sometimes. Lastly, maybe you could develop something on your computer, some kind of project, I dunno, ever tried level building for games? Or maybe learn a computer programming language? You could then section off 1-2 hours a day for this so you're still using the computer itself.
Oh and also, think of your eyes man, your poor eyes.