I know exactly how you feel, im doing the same a levels as you but instead of struggling with maths, im stuggling with the chem side of things. I'd say the best thing to do is ask your teacher/head of year for support. maybe if you speak to your head of year they can chat to the maths department about it to save you doing it? depends on how well you know your teachers and your level of comfort with them..all you can do is try your best..i have a few friends who got an E and U in their exams last year (we do AS levels too? not sure where you are so you might not do this) and theyre continuing on but honestly its up to you..suppose this is moral support more than helpful support so sorry bout that but just try your best, your grades dont equal your value as a person! also you could retake the exam if you feel it went really badly afterwards..usually people do a lot better in their retake exams! xx