First, ask yourself, what am I missing out on by playing games? I'm going to assume you wouldn't have asked this question if games weren't a serious problem, which usually means they're taking up too much time.
I'll say what I always tell people trying to overcome game addiction: games are are not inherently bad, but missing out on the rest of life because of games is definitely a problem. I love games, but there are absolutely things I'm not willing to miss out on just to play games.
So if you're struggling to stay away from your games, what you need is less to force yourself away from games and instead allow something else to fall naturally between you and games. Do you have any hobbies? Do you play any sports? Do you have friends who like going to movies or hanging out at the park, or even just like getting together for lunch or something? Remind yourself that there are plenty of other things that can be fun besides playing games.
The other major issue most people face when games start consuming their lives is the neglect of their obligations. This can be the hardest part to deal with, because you are trying to replace something you actively enjoy (games) with something you don't (work, school, chores, etc.). This part is going to take discipline, which is always something that's easier to hear than it is to live. So here's a disclaimer: It's going to suck. Forcing yourself to give up your justifications (I'll just play one game, it won't take long, I'll have plenty of time to do those other things later) is not only difficult, but almost physiologically painful at first. Learn to put the stuff you need to do first. No exceptions. One more time: NO EXCEPTIONS.
Lastly... make some time to play games. Yes, really. No person is a machine, and leisure time is actually quite good for you when done in moderation. So if the housework is done, and your work for the day is filed away, and you've spent some time on that hobby you picked up. play a good game to unwind. Remember though, that this step comes LAST. Discipline first. Reward later. And be honest with yourself. Chances are, if you're rushing your work just to get to game time at the end of the day, you aren't disciplined enough yet. Push yourself. It can be done. Get someone to keep you accountable if you need that. Being addicted to games is honestly nothing to be ashamed of. It's fairly pervasive, but it can most certainly be overcome with time, and maybe a little bit of help.