Simply you have to stop studying after 10 pm. This is not the perfect time to study though. You should get up early in the morning at about 5.30. Read all the theoretical subjects ( mainly Chemistry ) in the morning. Solve math at night.

As you feel dizzy at 10 pm, it is perfect time to sleep as per your body clock. You will get up at 5 am in the morning without any alarm if you sleep at 10 pm.

Hope you get my point. All the best.