Hi, so right now your GCSE grades are on the whole too low, as it is recommended to get straight 9s. However, it would depend on your postcode area. I recommend you do some research on whether your address and your school are considered as less advantaged.
Seeing your enthusiasm however, I believe it would be best you do lots of UCAT practice over the summer, and in these few months before summer try to skim over all of your A level courses in order to brief yourself and gain A*A*A*A* for your predicted A levels.
The reason I put lots of emphasis on UCAT is because, I believe, as in I have read somewhere, that Imperial considers UCAT score highly, and perhaps exclusively (if my memory serves me right). This would help you to overcome the barrier which is your GCSE grades.
I recommend you apply for Imperial with one of your 4 slots. It ranked higher than Oxford on university rankings last year.
Now, your A level choices are already optimised in that, almost every medical school requires chemistry A level, and Imperial, on top of that, requires Biology.
Make sure to prioritise your Maths, Biology and Chemistry over EPQ even if that means it needs to be dropped. Cambridge and Imperial do not consider UCAS Tariff Points so EPQ will not be that important.