Sleep, or lack thereof

I have been sleeping terribly for the last few nights averaging between 4 and 5 hours despite going to bed at midnight and waking at 8am. I am generally awake from 3 to 6 am staring at the ceiling, reading and wondering why as a usually world class sleeper, I cant manage to get a decent 7 hours plus of quality sleep. So far large amounts of caffeine are staving off fatigue but its not going to be pretty for long. I was going to post this at 4am but my battery died.