Dear, this is not a typical problem. Majority of people are like you. Very few are able to stick to the task and continue with interest in what they do. That happens because of their dedication to the task they are doing. Usually such people will be able to achieve very high goals. You come in the average group, I hope.
You need to define your goals. Nurture your goal and love your goal. You need to self motivate so as to do everything to attain that set goal. Once you do that, you should set creative ways to train yourself. Love, affection and dedication towards your goal and the way you approach the goal are essential.
Don't worry. Even if you don't follow the given steps, one day will come, when you will be compelled to perform. Take care.