Distorted thoughts (if depressive/unrealistic) have been found to be related to certain chemical imbalance in the brain, to create that balance medicines are prescribed. Secondly if your anxiety is long term it cannot be cured in 2-3 months, but it can definitely be controlled or the impact can be reduced in few months. Anxiety itself can go away with time. Talking about your fears is the first step so talk about it with your parents, friends do not ignore or avoid it. Why are you getting such thoughts of death, can you elaborate?
Next Steps
Do lot of deep breathing a must and multiple times a day. Keep away from mobile/gadgets at least 1 hr before going to sleep.
Health Tips
Dont try too hard to sleep. Until you fall asleep on your own, dont lie down. Which activities relax you? Music, a badminton game or watching you favourite show...take out time if you can to relax your self. Plan you preparations and act. Learn to say STOP to your unnecessary thoughts. Look at your goals of life what do you want to become, keep telling yourself to reach your goal you have to clear the exams hence study. ok. Wish you all the best! I know you can do it. You can defeat your unrealistic thoughts with real action.