Try a power nap
There is some evidance that naps
of 45 min to an hour will not mess with your regular sleep
Set the alarm yourself and get up, even if you are still sleepy. Regardless, try to keep your biorhythm clock consistant by arising at the same time every day, even weekends. If tired you can go back down after 5-10 minutes, otherwise you may have difficulty getting back on schedule.