In addition to what Lili and Banhawy said, try to remove all kinds of exam nerves from your mind. Convince yourself that you're studyin for yourself, for Allah, but not for the exam. I guess this way you'll be more relax when studying.
Also, try to start as early as possible, when you've just woken up, u'll be so fresh, concentrating and in a study mood. After fajr is the best way to study. Believe me, i've tried it and you'll memorize very quickly at this time. Writing was always useful, when you write what you study, you're more likely to understand it n memorize it.
Bare in mind that "It's the Quality, not the quantity", so don't stress yourself so much, try to concentrate in the moments you're studying.
Last but not least, pray to God and have faith in Him and that He will not let your hardwork go in vain.
Good Luck sister!!