sounds like common symptoms of anxiety/stress

since you have a big exam coming up-this would explain your symptoms

try doing these things

-stop eating at least 2 hours before bedtime. this gives your stomach the chance to digest everything. sometimes digestion can cause restless sleep.

-avoid eating spicy foods before bed. these can cause restless sleep and nightmares.

-take a warm shower or bath right before going to bed-this helps relax your muscles and ease your mind.

-try using a nature sound machine (if noise doesn't prevent you from sleeping). alot of people (me included) find these soothing and will help you sleep easier.

-develop a study routine that allows you to get adequate study time in well before going to sleep so that you have time to relax afterwards and can feel at ease, knowing you've prepped for your upcoming test.

-if all else fails, you can try taking tylenol pm or benadryl to help you sleep but don't use them as a nightly routine. if you are having chronic issues w/insomnia talk w/your dr about a prescription sleep aide.

hope you feel better soon