Why feel strees = cause lack of early preparation before exam.... if you've prepared earlier... then you'll feel confident and you'll be ready for any obstacles awaiting.
Your saying : I feel stress because of exam.. Real cause, I'm lazy and dun wanna study for it... watch TV better
=> Permanent solution : try change ur habit... learn to enjoy studies a little bit... you'll find it easy to learn if you actually pay attention to it... and understand the process... Studies is NOT about dead memorising... its about understand how things work!!
Ways to lose stress:
i) Study!! Dun be slack! Study 40 minutes... Go walk around the house.. drink some water.. hop around the house.. then continue studying... Don sit there and study NON-STOP for 10 hours...u'll be BRAIN DEAD and ur brain wont keep anything in it!
ii) Dont waste your time!! especially when exam is near.. Dont go cook this or that.. don go fren house to play / study together. DONT GO SHOPPING! Dont DAY DREAM! More time = More time studying = more confident and ready for exam
iii) [not advisable thing] many say that masturbation/sexual intercourse reduces stress... not sure that works a not... but LOL! It might in the term of pleasure. Depends on individuals

If you have eating disorder when stress comes.. why not DONT STORE so much food in ur house!!!! An amount that is sufficient to survive is good enough