this is the most ridiculous idea and it would completely backfire on you; if you were to actually go through with this, you would be feeling sluggish all the time, your brain wouldn't be able to take anything in, your immune system will weaken, you'll probably gain weight, and you'll be more affected by stress.
The best way of dealing with the hsc, if it scares you this much (and it must if you're ready to mess with your body in this way), is to get yourself into the best physical and mental state you possibly can, therefore you ought to get 8 solid hours of sleep, at least 30 minutes of exercise each day, eat healthily and do something to relax and get away from it all - anything from watching tv to hanging out with friends - and don't beat yourself up over allowing yourself to 'indulge' in these kind of things.
Realistically, you're not going to spend the next year studying/stressing til 2 am then getting up at 5 so you can study/stress some more, and then continue on like that until you've driven yourself insane and totally burnt out one month in.
Just continue with your life as normally as possible, and relax - the hsc is not that bloody hard.