What is my purpose of life?

I have been listening to this song by Yiruma. The title of this song is Time Forget. I am slowly falling in love with this song. It bring peace to my heart and calm my thought but... out of a sudden i have a feeling in heart. I started to close my eyes and feel the sensation. Why, why is it like tat? After my sophomore year, I have changed a lot. My attitude towards my study, my attitude towards my future and my discipline. My college life is really totally different from my high school. I have more fun and waste a lot of my time in games and hanging out with friends. I started to feel that I don't care too much of study anymore not like before where I was still a high school student. I still remember few years back, I am still a high school boy struggling to achieve good results in my SPM. I struggle every moment in my life just to get what I aim for. At last all my hard work paid off. But now i am totally a different person. I am not struggling anymore. I give my self a lot of freedom. I have already forgot my purpose of life. I feel emptiness inside me. Although I have been chasing and finding happiness almost everywhere. I hang out with friends, I play computer games, I watch movies but all this happiness and joy is just temporarily. When I am alone in my room, I felt the loneliness, emptiness again. What is the use of chasing all this? In the end what did I get?! Worst result! Bad health! Bad mood! I neglected my study, my future and myself.