Hi! I didnt do GCSE dance but i can give you some general advice 🙂
The first thing I woulg suggest you do is to talk to someone at school about this (or send them an email) and ask them what your options are for the subject. You could speak directly to your dance teacher depending on how they are generally, or if you think they’ll not understand properly then maybe someone with pastoral responsibilities like a head of year or form tutor.
What grade are you working at, if you’ve been given one? If your not doing well in the subject from that angle and youre not enjoying it then mention that to someone at your school because whilst it is late to swap a subject and you’d have to catch up there may be an alternative they’re willing to offer depending on their specific policies on this kind of thing.
A couple of people in my friend group (including me) sat out one subject at gcse for one reason or another. I ended up not going to pe anymore and being allowed to do homework instead due to my situation in school. One of my friends dropped computer science and instead was set work for English because he was struggling with that. Im not suggesting you take either of those options but im just letting you know that things like this do happen in schools so they may be things your school can suggest if you’re struggling to the point you dont want to take the class anymore- or they can help you integrate into the class better. You could also try and improve your dancing outside of school if it’s something you enjoy and want to get better at.