The one thing I really like about maths is that the answer is either right or wrong

PP, you are in for a treat.

As you progress through maths that ceases to be true. I have a friend who studies physics at Oxford. There they can't even agree on whether a straight line is actually straight, or just part of a circle of infinite radius.

I struggled with maths terribly. My weak short-term memory and poor sequencing skills made it particularly difficult. I can't hold a pattern or a sequence of numbers in my head for longer than a few seconds. I would miswrite equations and get the numbers all jumbled up. And so much of it just seemed staggeringly illogical - I could never see the purpose in half of what we were trying to do.

I had to do two hours' extra maths per week in the special needs department. My special teacher was very patient with me but I still hated every moment of those lessons. I passed my GCSE exam in the end, though - I got a C. I got A*s and As in my other subjects, but that C meant more to me than all the starred As - maths was so difficult and I'd had to work so darned hard for it. I danced when I got my certificate. Literally.

In GCSE maths there is one way that you're supposed to work out sums, for each type of sum you get a single method that you should use, other methods lose you marks which i see unfair.

I don't think that's true. In my school we were allowed to use any method we liked providing we showed our working - the examiners like to see how you've arrived at your answer. The teachers would only show us one or two methods for each topic to prevent it from taking up too much class time, but providing you've got the right answer and it's clear how you arrived there, I doubt the examiners will penalise you for using an original method.