I got 5 A*s, 4 As (one of the As was in english literature) and a B in English language. I also struggle in English. I was originally going to apply for medicine but decided I preferred dentistry better due to more contact hours and that I'd be using my hands more. The requirements are very similiar, I would even say the same, don't worry about GCSE results. Obviously, the more A*s the better. THe way you should think about it in , is yes there will be applicants getting 8 or 9 A*s who get in. But certain unis take this into account more than others e.g. Liverpool(for dentistry at least). Therefore I am applying to unis that look at UKCAT scores more so Newcastle, Glasgow, Dundee and Manchester. If your capable of doing medicine you will get in. There will be a uni who is looking for an applicant like you while other places will be looking for a different types of applicants. Also I think you teacher was trying to stress the chill people out not you. Also, there will be even more places per applicant compared to previous years when you apply so you will only be even more likely to get in. The only thing that is really paramount is not get Cs and getting As at A level. Anything else , UKCAT score and personal statement, can be fixed with a gap year.