Staying awake for a long, long time

I have done 2 exams and have 2 more to go. One of them is this coming Monday and requires a significant amount of studying and memorising the info. It's a parrot-fashion learning kinda module and well, I'm feeling more like a tired person than a wide-awake parrot lately.

Now, I work every weekday and get up at 05:30 every morning and sometimes manage to get half an hour or an hour of study in before work, depending on traffic and then later in the evening, I manage 2 to 3 hours before I flop into bed and as a result, I am exhausted.

We are also currently only living on take-out as I don't have time to cook and then study and well, nobody else is prepared to cook and I suppose that you can take all the vitamins that you want, living on margherita pizza and ostrich piquante global wrapps will not make you any more healthy and will not really contribute to a feeling of overall "awake-ness."

This leads me to my two points:
1. I am running out of time. Criminology isn't difficult, it's easy but it's a LOT of easy!
2. I need to study through Friday night. Right through, yes. And then through Saturday day too. But how?

I have had various recommendations, none of which I'm terribly keen to try, and so I was hoping for some miraculous insight from some wonderfully clever or experienced person out there!

Just a few guidelines:

1. I don't do drugs. They are bad and permanent or even semi-permanent brain damage is not an option.
2. I do not stand on my head. By itself, attached to my body, with my feet or just as is attached by itself. Read it carefully, it does make sense. I mean, I don't hang upside down resting upon my head and nothing else. It gives me a sinus headache and makes me look like I'm terribly embarrassed.
3. I don't drink much coffee. two cups is more than enough and more than that will irritate my stomach, pack on the cellulite and just stress me out even more.
4. I do not handle large amounts of sugar or tartrazine well. I get hyper and bounce around like a 5 year old and then I get VERY cranky.
5. I live with two other people so I can't scream or play loud music or anything else.

O.k, those are the guideline. Any help would be great. Ready and go...