*Night-life*

Everyday i just can sleep at 3 or 4 o'clock in the morning..I don't know what happen to my brain..It cannot function in the morning when i need to study but it only function at the night or in the mid-night..Yesterday i lying on the bed for 2 hours then i cannot sleep,at last i went out to yam cha at 3 o'clock in the morning...Then the next day lecture class i fall asleep and cant concentrate on what the lecturer taught..Help me to change my time to the normal world..