Hello.. Well seems like signs of depression..I gues the stress,the competition you face at your age makes you feel like that.. I suggest you to talk to your family and close friends and let out what you feel..don't keep things bugging you...go for a short trip so that your mood changes...you need some change happening...try indulging in your hobbies..or something that you like..as in cricket,swimming, gym or anything... Do not worry... Am sure youll be pulled out of it