You are in Year 9. I promise you now that year 9 means nothing. The grades they are giving you are probably false, there is no way you're getting As in GCSE level work in year 9. Honestly, I wouldn't worry in the slightest.
You have to start working hard in year 10, but year 11 is the only year that actually defines your GCSE grades. I didn't start listening in lessons until Year 11 and I still got all 8s and 9s.
You will be fine. Do some work of course, but if you can't then don't worry seeing as you've not even starting the GCSE course yet, and even if you have, you have three entire years to do it.