Forced to make a sacrifice

My exams were getting closer day by day and from the moment I was introduced to a computer game by one of my friends, my grades started to decline.
My friends at school were discussing with me about a computer game that I was playing with them when my teacher, Mr lim, called me up to the front. I was astonished when Mr lim asked me to come up to the front as I never did anything that could have caught his attention. " I called your parents about your declining grades and they have told me that you have been recently addicted to a computer game." At that time, I felt betrayed by my parents for telling Mr lim about the computer game. " Why do they keep on saying that I am addicted to this computer game? I only played it for around 3 hours a day." I thought to myself. " Mr lim, I do not think that this computer game is affecting my grades as I still do study." I replied to Mr lim. " Even though you still do study for your tests, I still think that you are still affected by this computer game, at least give it a thought to stop playing computer games for awhile until your exams." encouraged Mr lim. I listened to his advice for a moment and gave it a thought, but decided that I was not affected by this computer game and would not be affected by it and ignored the advice.
The next day, I was given a mock exam by Mr lim to prepare for the exams. "This would show them that I have studied for my test." I thought confidently to myself. I looked at the paper and laughed, it was easy! I started to write down the answers in the mock exam, feeling proud. However, not even one quarter through my mock paper, I started to drift off in the fantasies of my computer game and started to ignore the things that were in front off me. I did not realise that time was ticking away and my mock exam was still going on. " Wow...I really could try that when I get home...or maybe this..." I was locked up in my imagination when I felt a pat on my shoulder. Awaking from my dream, I looked up and realised that it was Mr lim frowning, he pointed towards the wall clock. I looked at the wall clock and almost jumped out of my chair. Only ten minutes left! I scribbled through my paper as quickly as I could and finished right on time. I was disappointed and embarrassed in myself for getting distracted by a computer game.
Mr lim heaved a sigh as he took my mock paper. "Meet me at my cubicle after school." he said.
After school, I went to Mr lim's cubicle. He took out my mock paper and showed it to me, he had already marked finish it." I realised that you were daydreaming for a long time during the mock exam, were you daydreaming about the computer game that you are addicted to? You know that you should have stop playing that game a long time ago and concentrate on your exams?" Mr lim reprimanded. After Mr lim finished reprimanded me, I gave a serious thought to my addiction and decided that I would sacrifice that computer game for good grades and not letting Mr lim down for his concern.