the best thing for you to do, would be to really make the most of what you know, think about the multiple choice and short answers productively etc... and u shood be able to get around 40/60 at the lowest if u know simple concepts etc...
put something down for every answer, and if ur not sure write HEAPS because they dont mark you down for whats wrong, u get marks for what is right.
and for the essay... even if u only get 4-5 pages out itll be worth the effort
youll be fine matey just take it easy.