chronic asleep-at-the-wheel

I would like to know how come I  am so friggin tired all the time.   My head hurts either at the base of my neck, or around the temples.   A friend of mine asked if I might have Narcolepsy.   Maybe i do, as soon as I sit down I get sleepy.  

That is not good particularly since i am trying to study for my last final exam for spring quarter.  I no sooner sit down to study then I am nodding off.  I have tried for 3 days now to study and I can't stay awake long enough to get through my notes.   It doesn't make any differrence if I take a nap, i still can't stay awake.  I don't know how many near misses I have had when driving home, falling asleep at the wheel.   I often call a friend of mine to talk to me while i am driving home, to keep me alert but sometimes he is not available and that is when I know that I have a guardian angel watching over me.  I have no idea if i nodded off for microseconds or seconds or longer.    Regardless it is not good.   

Does anyone else have trouble staying awake?