I'll give you some insight into me, and what I did, etc.
I'm not quite in the same situation as you, but I did Chemistry, Maths, Biology and English Lit for AS, dropped English Lit for A2 so I could focus on sciences more and have a stronger approach to being dedicated to medicine.
I think in some ways physics replaces maths, but having said that, I think maybe you should drop English at A2 and pick up maths at AS. That way they'd know you're not incompetent at maths
For GCSEs I got 6A*s, 5As, 2Bs (music and drama
), I don't think they take GCSEs much into account, as long as they're semi decent, should be okay. Post them and we'll be able to further advise you?
But look, medicine is tough to get into anywhere, as long as you're determined, you get As this year and you do well in the BMAT, you should be in with a fair chance.
I'm a crap candidate in terms of grades etc compared to others, but I improved at AS even though my school had classes of around 20-25 students in each
just show them you're determined!