For any healthcare related degree, you need access course (or other A level equivalent) AND GCSEs in Maths and English. Unfortunately, this doesn't sound like the system failing you, rather gateway people assuming you have the equivalent to UK GCSEs.
Keep trying for your GCSE maths. I understand that failing feels pretty rubbish, but you need to keep working at it and trying if you really want to do physiotherapy at uni.
Good luck with it.