see most of the people have two hands ...when you cant take the load from 1 hand try to use both of your hands for that...ncert books are very important from iit jee viewpoint and aieee too...try to concentrate on your ncert during weekdays and just make your notes too good and read them after coming home at 9 everyday...sunday is the day when you shud gear up whole of your strength and give atleast 14-15 hours of self study(forget that you are a human living for sleep,food,cleanliness etc etc...) espacially for iit-jee this will be your 2nd hand...try to utilize this day and it will make a difference between rank and no selection...and try to concentrate more on topics which you feel you are not ok with and divide your time amongst all the subjects...practise as many questions as you can in mathematics,physical chemistry,organic read as many books as you can in physics,inorganic and give your preferences to topics which are of more weightage and scoring in jee like probability,modern physics,thermo,salt analysis,dynamics espacially fluid...you must know the intermediate steps in any orgnaic reaction..and thats it and dont forget to worry your teacher by asking as many doubts as you can not hinking about whether people laugh or think you as a fool ...