First make a timetable....don't burden yourself by studying toooo much. also just by studying u wont be able to score well....after one week of studying one chapter, revise it...if you take say 2 and a half hours to study the chapter for the first time, keep 1 hr aside a week later to revise. Next, revise all the portions that you have covered after 21 days of studying(if you can study subs like math and other things you will require lots of practice and revision for at first) this way you will remember for a VERY long period of time...that i gaurentee....!!!!!!!!!!
HOPE THIS HELPS!!!!!!!!! :)
AND BEST OF LUCK!