Hi
@Username2727,
I can understand your dilemma. Both chemistry and physics are great subjects, and it can be difficult to choose between them.
Personally, it sounds like you enjoyed chemistry more at GCSE, which is already a great sign! I took physics at A-level, and I absolutely loved it. However, I did also wish I had taken chemistry, since I've also loved that subject and it sounded really interesting to me whilst I was taking physics.
Ultimately, the best way to decide is to think about what you want to do after A-levels. If you're sure that you want to study maths at university, then either chemistry or physics would be a good choice. However, if you're not sure, then I would recommend taking chemistry.
Chemistry, and I do hate to say it since I love physics, is probably a more versatile subject than physics, and it will give you a broader foundation in science. It will also be more relevant to many different areas of maths, such as statistics and probability.
Of course, at the end of the day, you can always change your mind later on. If you start studying chemistry and find that you're not enjoying it, you can always switch to physics. Plus, I've found that Youtube videos on physics tend to be more understandable than those on chemistry, so you can always find more resources for your curious brain there!
I hope this helps!