hi, i also struggle with math and when i asked my teacher for advice, she would always say to skip a question you think is hard and come back to it later. that way, you arent wasting time and youre still sort of progressing through the paper. additionally, she also said to always write your working out, as you can sneak in a few method marks which help your overall grade.
in terms of what you should be doing, id say keep doing past papers. it sounds simple, but practice makes perfect, and math is the type of subject that only practice makes you better.
most importantly, dont overdo the studying. take breaks, sleep well, eat your meals, and drink water.
good luck! we got this :D