Sounds good to me, you’re dedicating £thousands and 3 years of your life to it, best get it right.
I am no UCAS expert so apologies if what I’m thinking can’t be done.
Couple of questions I’d want answered or at least pursue:
Can you email the offering Uni admissions departments and find out if they’re amenable to swapping you from CS onto Physics? If they are, that’s options.
Have you discussed with your academic or form tutor in your current school on this. While they might not be able to give you a full Oxbridge work up as if you were attending they may be able to provide some support, and I’m sure they’d want to if they’re able. Even if only materials and helping with an academic reference. It’s possible, if they were minded, they could cram some Oxbridge help in at the end of this year while you’re still on their books as a full time student.
I do know my daughter’s school can offer some assistance to re-applicants which is I guess how they may treat you.
If you’ve the grades ‘in hand’ later in August you’ll know whether you’re in a position to get an Oxford application through.
Also last of all, have you visited these Universities? In particular St Andrews, I’d strongly recommend going to see it (and the others). It is a little further away than most, and a very small town. Check you’re happy with the Physics dept in comparison to the other Unis you are looking at.
My background, I went to St Andrews 1992-96 for Physics. My daughter is an offer holder for a humanities subject for Oxford this year.
Bearing in mind the elements of an Oxbridge application are:
Personal statement
GCSE grades and either A Level predicted of achieved
Aptitude test score
And most importantly:
Interview performance.
Looking at those the school if minded could help you with the personal statement now, and possibly interview prep or at least materials for the PAT.
You’ll definitely, if you get that far, want to get some form of interview familiarisation or practise - even if it’s getting a friend or family member (or a tutor?) to run something with some typical questions you might get. It’s all about ‘how’ you approach the question, not getting the correct answer.
However I well remember the end of this academic year when I did it in 92. It can feel hard to keep everything on track for the actual exams- that’s got to be the No. 1 priority. All these offers need the grades, distractions should be carefully managed. If the Mocks were not quite the outcome you wanted, keep studying and it’ll come good.
Good luck. And, I am no expert. I did not get into Oxford and I can’t say I did very well in my Physics degree either!
Definitely, get a meeting with your form/academic tutor in your school. They’re best places to advise you. However always remember, if you get a clean sheet of great grades it’s your choice come August, not the schools!
Good luck. 👍