You are not alone with this problem of addiction to various bad habits. Modern society is conducive to all these bad habits, including video games, porn movies, etc.
It is very difficult for many people to see that a simple life focused on contemplation is the best life. I have not even watched a movie for many years and I do not miss that at all. Such activities never even come to my mind. I live in a fairly large city in the US but I am not bothered or “attracted” to any enticements that surround me.
The root causes of ALL kinds of sufferings are associated with dasa akusala. But there are various levels of them. One needs to start dealing with the strongest ones first.
Those are the ones that one does with the bodily activities and speech, which I call “the big eight”. These are discussed in “2. The Basics in Meditation“. It is a good idea to reads that section: “Bhāvanā (Meditation)”
It is useless to try to comprehend deeper aspects like Tilakkhana until one’s mind can see that such actions and speech can lead to a high level of stress in the mind. Those actually have origin in abhijja (excess greed) and vyapada (excess anger), and miccha ditthi (10 types of wrong views) in one’s mind.
– As Cubibobi mentioned, getting rid of wrong views (miccha ditthi) is critical.
Initially, it will be hard to stay away from old habits. So, it will require determination. Whenever you get the urge to do something “bad” just start reading or listening to Dhamma or engage in one of the activities discussed below.
It is also necessary to have good eating habits and to engage in an exercise program. Just going for a run/walk will do. Yoga is another activity that you can even do at home. I started yoga more than 10 years ago. I just bought a couple of books and learned. Also, see this old post: “Spark” by John Ratey”
– Reading books is another way to keep the mind away from video games, etc. See, “Book Reviews”
– Another is to keep the home environment clean. What is needed is not expensive furniture, but a simple, clean environment. If you have seen a Buddhist temple, you get the idea.
– Yet another is to associate with those who have “good habits.” Even spending time on this forum, you will meet “good friends.”
Finally, the following posts could be of help:
“Is It Necessary for a Buddhist to Eliminate Sensual Desires?”
“Craving for Pornography – How to Reduce the Tendency“