Throw your textbook into the rubbish bin ( just joking)
Learn the concepts through solving different types of questions. After a while you will realise they are asking the same question every time. 20 short response and 1 extended response on daily basis should be ok. ( This is not difficult. Just imagine I used to solve 100 multiple choice type questions each day in Turkey) So you are lucky. And most importantly, REGULAR STUDY, REGULAR STUDY, REGULAR STUDY! I studied maths throughout the holiday and left the rest of the year for English. It doesn't work that way because I struggled when I came from a long recession of maths. Yeah, I'm exceptional because English is my second language and I had to spend much more time on it. But you have no excuses at all! Start studying now if your aiming 40+