I've the same issue, but it's because I am more of a night person and like to stay up until 2 or 3 in the morning. What time do you go to bed? If this is the case and it's quite late, try to adjust your sleeping schedule by setting back the time you go in by a half-hour or so each night. It's important to do this gradually so that your body clock has time to keep up with the adjustment. Doing all this in one night might make it hard for you to fall asleep.

Hope this helps. I usually have to do this beginning the second week of August for school, but I have to be to work at 10 am for the next couple of weeks, so I've got to start tonight! Fun's over for me I guess.