Oh my eyeballs! Now i know how it feels to be infatuated heavily to someone of your same age. The bigger problem arises when the person is in your class. Many people hate this feeling. During lesson time, we are supposed to study and not concentrate on other things. Then the weirdest thing is that the person's image would pop up and go off suddenly. You would feel "Hey is someone playing a trick on me?" Well that is your imagination. It takes a harder effort to diminshed the person floating around our mind during exams time.
Learn to close your mind. Learn occlumency from Professor Snape. Well, thats why we are humans. Its very hard to control these feelings especially to a person with the same age. If a person has no mutual love feelings for their same age group and suddenly feels that for the person, wouldn't you think it is weird? Well, it is strange.
Now another problem arises. the person you are infatuated with might be interested in one of your close friends. This is a difficuly and tricky problem. However, it is the person's choice so we should be happy for the person. Furthermore, life is cruel and we should just accept reality. What if we don't like losing? Haha. Lets hope time will choreograph the situation into a better scene.