Firstly, be positive everything goes fine. If you are healthy, your mind will be healthy can resolve so many problems smoothly than with a stressed mind. Take a deep breath.
Now, After completing 6 hours of daily class you should take a nap of 1–2 hours. Then start your further study. Give equal importance to all subjects and study them daily either it will be physics, chemistry, biology or English, physical education\ Maths. For Literature, read 1 chapter daily or if you have Mathematics, then do 1 exercise daily.
Now, Let’s come to our main subject i.e, Physics, chemistry, and biology. Each subject has equal time to study in the case of physics and chemistry. For 30 min read theory. For another 30 min practice questions related to what you had studied. It helps you in getting a grip on each concept. You may take the same pattern in each subject. It will neither burden you nor and the last minute you will face any difficulty.
I hope it will help you.