Clock Watcher

I have become a clock watcher. Not during the day but during the night. I go to sleep when I get tired but after only 5 hours I awaken. I guess my body has had enough sleep. The fact is that I awaken at about 4am and since I am not a night worker, I don't start my day. I look at the clock and try to go back to sleep. After what seems like a few hours, I open my eyes and look again only to find that 2 minutes has passed. I do this for the next two hours until I get up for the day. By that time I am exhausted. Clock watching is a hard job.