Stress

I am VERY stressed right now.
I just can't get my head to straighten out.
Have you ever been this way, where you have so much to do that you just don't know where to start so you end up not doing anything?
I am at that point.
I have a presentation on Saturday at school.
The PowerPoint is finished but I have not heard from my study buddy Andreea with her imput.
I also have homework that is due that I know I will not be able to finish. (shame, shame on me).
The very last and biggest thing is that I have an exam that is covering some pretty abstract concepts that the Prof. is going to create workable problems.
MY HEAD IS NOT WRAPPED AROUND THIS AT ALL.
I have ONE day to cram all of this into my head.
I need to take a deep breath and start with one concept and work from there.
WISH ME LUCK!!!
I REALLY, REALLY NEED IT!