feeling sleepy when you HAD to be awake but you juste WANT to lay on your bed and sleep is something I HATE too.
I remember I used to stay awake until mornging sometimes because I had tones of homeworks and my eyes were slowly closing and most of the times I just couldn't keep my eyes open and when I was able to keep them open i was just not capable to think properly so...
By morning I often found myself sleeping as I was still sitting in front of my desk, sleeping and drooling on my homeworks... memories memories.
I hate coca and coffe so that was not an option for me... I just could put the music very loud but even the loudest music I had at home made me feel sleepy (Linkin Park's Chester's screeming voice sounded so soft and sweet to me at that time... a veritable lullaby...

)
So I slapped myself..... that didn't really help and work.
I'm so glade I'm done with those never ending nights with homeworks and exams and tests... (well not exactly done but kinda lets's say)