I done foundation maths in year 9 and 10 before getting moved to higher tier. Then I was predicted a 6 in my maths gcse (covid year). Then in year 12 in my first maths mock I got a D then I vividly remember going crazy with maths revision in 2020 december, fast forward to AS results day I got an A in maths. Then in year 13 I was pretty consistent with maths and ended up getting an A in actual A-level exam. I must admit that most of my marks came from pure maths. Mechanics n stats tend to be harder. Im a 2nd year student at KCL now. To answer your question is maths hard? No. Definitely not even though I was at a major disadvantage I was still able to do well. It's a subject that requires a lot of practice however. The jump from year 12 to year 13 for maths is crazy tho. You start learning about the different ways to integrate and differentiate and more about trigonometry.