Are you going to all your lessons? Do you understand the work? You need to go to all the lessons and if you're not getting it then you need to speak to your teacher every time you're not sure. Get the CPG book and use that to help you revise, keep reading over the material during the holidays to help keep it in your memory, do the practise questions. Go on the physics and maths tutor website and practice using the questions there. Go on youtube and search for teachers going over the maths syllabus - you need to understand the material for this to be helpful though. Look up past papers for your exam board and do them all for the past few years before your real exams. Most importantly though go to all your lessons and practice as much as you can.