We were generally told that you need at least 6 A*s at GCSE to do medicine - so for you that'll be about six 8s or 9s.
Your maths is really good - you're almost there - but you probably need to work on improving your chem & bio grades. I mean, you'll need 7s in them at minimum, probably 8s realistically.
Just remember though, you can work in medicine even if your grades aren't quite good enough to be a doctor - you could be a paramedic or a nurse.