I am a teenager, and have a slightly high Cholesterol level?

Hi, I had receantly gotten a blood test done. When I went to see my results my doctor had pointed out to me and my parents that my Cholesterol level is slightly high (not by much, but a bit high) and he recommended me to take some medication. He had prescribed me 120 capsules of Lovaza which I have to take 1 times a week, but this worries me because I am only 15 (in 1 week i will turn 16) and that I feel this is not a good sign. I am slightly overweight as well, but I play baseball, workout and also do a lot of jogging and my doctor says the reason for my overweight problem most defenitally looks like a genetics thing so its something not to really stress about. But one thing though i found wrong was during the day of my blood test, I had ate a corn muffin and 12 oz of Chocolate Milk and then I had tooken the test which I wonder if it has anything to do with making my blood reports void or such. I searched online Lovaza it just looks like some capsule with Fish Oil (Omega-3-acid ethyl esters). My main question is, should I take these medications and if I do will it be for lifetime? or temporary? I really am nervous and my parents really expect me to take care of this problem effectively. Please give me advice and a solution, thanks!