How to deal with stress that i am having as i'm not prepared well for final exam which is in 20 days. further i can't concentrate on my studies?

Study!Herbs can help: The best strategy would be to study so you feel prepared. Lots can be accomplished in 20 days. Med students preparing for exams who took rhodiola performed better & had less stress. L-theanine & holy basil reduce stress while helping concentration. B vitamins & magnesium may help. Eat well, get enough sleep, take breaks to exercise, focus on the moment as you study instead of worrying. Good luck!