sir,i am young boy .when I do some work,I fill i am the best in the world.after few time I lost my interest.when my parent angree with me,I understand that  understand that but dont full fill that problem.i also angree with my parent and i do any thing worng.actually what is my problem i dont understand.plz suggest me.
It is difficult to comment specifically about your problem from such small history. However, I can guide you what may be there. First possibility is features of bipolar disorder. And symptoms you described may be part of manic or mixed episode. Second thing you may be in stress either of your study or work which you may not able to cope up with. Third it may be due to some development issue during your growing period. Consult a psychiatrist with your parents so can reach proper diagnosis. And later on you van be treated with medicines and/or/ counseling.