I cont sleep any more at night time why... ?

When i go to bed it takes me 3 hours to get to sleep. Sometimes i can get to sleep after an hour then wake back up within a half hour. I find my self not getting to sleep till its morning time some how i seem to sleep when its light out side. But i only have about 3 hours sleep. Whats wrong with me? its very difficult to have a social life as i am tied throwout the day.