Don’t put too much pressure in the name of national level competition. You are aiming to clear it to face even more stress and further at one stage the stress of saving someone’s life.
It’s just the beginning of your preparation. Stay focused towards your goal. You’ll get good marks in tests and bad ones too. Try to maintain your rank if you are giving national level tests of Aakash/Allen or any other institution.
Listen to your teachers. Not all but at least a few of them. Never ever get depressed due to your marks if any instead work towards it.
So, in short. Tighten your seat belt for this roller coaster ride.
All the very best.