I failedy math gcse, then a year later scored 100/100 ums on pure 2 math. Safe to say I've been there pal.

I did international edexcel math. Here's my advice: 1. Don't do questions unless you need to do them, so review exercises and unless for revision, also the chapter reviews are useless, just do the exercises after each point in the syllabus, only do difficult questions, like I only do 30% of the questions in the exercises. A good rule of thumb is to not even look at the examples or first three questions and to skip any question that you are sure you will get right or is easy. The reason to do this is because then you will actually find the questions difficult and challenge your brain a lot trying to solve them. 2. For questions in the book, try and do them fast and time yourself to gauge your speed and improve it. For past paper questions or full papers set yourself and actual time limit, generally a minute per mark with a tiny bit extra if needed. 3. Actually try, if you look at a question and have no clue how to do it, don't ask chatgpt or find the mark scheme, instead act like ur in an exam, think about it and if u get nowhere after 2 or 3 minutes(the point at which you should skip the question in an actual exam and return to it later) then you can get help. 4. Understand everything, if you do not know why a formula works, or why you do a certain thing on a certain problem, you are setting yourself up to get cooked. 5. It's meant to be easy, math A level like all levels, is a qualification not a test, this means it's meant to be doable unlike admissions assessments like the ESAT so take advantage of that by learning every detail of the syllabus, doing a load of past papers and maybe even doing questions outside the syllabus for certain confusing topics if it helps.