Make a timetable, follow it daily. Try to understand the concepts in a detailed manner by maybe taking the help of some videos, or notes, etc and then byheart the formulae. After that, make your own self noted which you can refer at times and can also help you for last minute revision. Don't forget to solve the mock tests as there is a pattern which gets followed every year - like the type of questions asked, etc. And remove the fear from mind that you are weak in maths and believe in yourself that you can do it and the you're half way there.

Best wishes. Thank you.