EEG in the morning

Well it is 2:40 in the am and I am awake but by choice. I have my EEG first thing in the morning and one piece of it sleeping for about 25 minutes. To do this, like last time, they ask you to sleep deprive yourself. Last time was pre-surgery so it was no problem as I was sleeping through the nights previously so I had the energy. This time around is different, in the last two days I have slept only about seven hours total so I thought no problem tonight. Well like usual I was wrong, I must have fallen asleep about 11:30 and just woke up. My problem is tonight I want to go back to sleep I feel completely drained. Having done my post surgery norm I woke up after at most three hours and cannot let myself go back to sleep. :( I mean what luck I have a night I am finally able to sleep and I have to stay awake. I will update tomorrow as to the EEG though I will not have the results complete.