Post Graduate Medicine

Hey, i'm going into my GSCE year this september so obviously have to pick A-Levels soon. I was wondering whether anybody's had any success getting into post-grad medicine? I've been advised that Chemistry A-level would be really difficult for me, although when it comes to applied sciences and maths i've actually always been able to keep up, it's just some of the stuff on its own that would come up in Chemistry A-Level that i struggle to understand. I really, really want to do medicine it's been my dream for years.

So, i was wondering if i were to take Psychology, Biology and English Language (provided my maths scores were okay) would I be able to get into a Biomed course. I understand that i'd likely have to take a foundation year, and i know that Uni of Salford does one. I also know that University of Birmingham do a Biomedicine course and require Biology OR chemistry and then an additional science (psychology). Then obviously post-grad medicine would be an ideal path, although i've heard it's competitive and a lot to get through, but I really really want a shot at this and I think this is the only way.

Anyone got any experience or words of wisdom?