Well you'll have no trouble catching up in some subjects which at GCSE level you can teach yourself with a good textbook. I'd recommend taking some tuition outside of school too so you have a better chance, but like you don't do your actual GCSE exams until next year anyway, so you should be good
Don’t worry, you’ll be fine. I was off all of Year 11 and did fantastically in my GCSEs. Just make sure to email your teachers for missed work, and maybe try some tuition. If you have access to it, GCSE pods is a great way to learn content.