Medicine to Physics: 2 Gap Years?

First - well done for going with what you’re genuinely feeling! As someone who chased medicine for a number of years (but changed mind well before UCAS deadline), I know how tough it can be to look at a completely different path.
2 years outside of education may be tough. Remember, when you do apply for physics the universities will look at your education history and see 2 years off. They will want to know exactly what you’ve done to make you a better candidate. Gap years can be useful, but to give yourself a good chance you need to ensure you can fill that time with employment/internships/courses to make you a better candidate.
Have you considered an apprenticeship? I know it’s not necessarily your first thought, but apprenticeships run all year round (with no national deadline), can be in applicable qualifications (ie; degree apprenticeship in Physics/Engineering), and obviously the benefit of 0 debt. I’d suggest you seriously have a look at what’s on offer; as that might be a great alternative to follow your interest, get a degree you’ll enjoy, and not feeling behind.
If not, definitely have a look at internships, a lot of big engineering and science companies offer paid internships, and that could be a great way to get knowledge, some extra cash, and possibly a job offer all in one.
And do still speak to your teachers for their advice, but that’s just some of my ideas above. I wish you the very best of luck for whatever you choose!

What was your fifth choice? As Med is only 4 choices? If you decline all offers you get you get UCAS extra and 1 last choice but ofc not guaranteed that the physics course you like is available ........ I would contact the relevant university and ask them if they would consider a UCAS extra choice and explain your situation and then put that university down. There is also clearing where courses come available again and you could see then if any appeal to you, this would save a gap year.
I don't think that many universities interview for Physics unless of course you are wanting to apply for Oxbridge. I think your extra curriculars for medicine could be turned around for physics, you could just change your personal statement and say whilst doing this and this you realised your passion lies more in the filed of physics and you have read this and this etc .

What was your fifth choice? As Med is only 4 choices? If you decline all offers you get you get UCAS extra and 1 last choice but ofc not guaranteed that the physics course you like is available ........ I would contact the relevant university and ask them if they would consider a UCAS extra choice and explain your situation and then put that university down. There is also clearing where courses come available again and you could see then if any appeal to you, this would save a gap year.
I don't think that many universities interview for Physics unless of course you are wanting to apply for Oxbridge. I think your extra curriculars for medicine could be turned around for physics, you could just change your personal statement and say whilst doing this and this you realised your passion lies more in the filed of physics and you have read this and this etc .

Hi,
I'm currently a Year 13 student and I've just applied for Medicine and got interviews back but I've realised that I really don't want to do Medicine and instead want to do Physics. I chose to do Medicine at first for many personal and familial reasons (I think you can imply the rest) and for the most part of my Med application I've been confused as to whether it's what I really wanted. I do all sciences and maths for A Levels so, in terms of academics I think as long as I get good results this year I will be okay to reapply for Physics.
The only issue is that all my supercurriculars are for Medicine and not Physics - like competitions, work experience etc. I've read and am reading quite a few books on Physics and have done the Chemistry Olympiad and Maths Challenge but didn't do the Physics Olympiad because I needed the time to focus on my Med application when the opportunity for it arose.
So basically I'm worried about what exactly it is that I can put in my personal statement and talk about at interviews - if I apply to universities that require interviews for physics or related courses. And I don't know whether it would be better for me to take 2 gap years rather than 1 - where in the first I'd build up my personal statement and in the second I'd apply.
Honestly, I don't want to take 2 years out of education but I'm perfectly happy taking one. I just wanted to know if anyone's done anything similar because I really don't know anyone who has and, apart from my teachers, I don't know who to ask about it. I also want to know whether I should take 2 or if anyone knows how I can build up my personal statement in the summer. I'm going to look into work experience placements I can do in the summer and read more books but what else can I do? Because I know a lot of competitions open at the beginning of new school years.
Also just general words of advice would be really helpful because as much as I am excited to finally be able to do what I want to do I am incredibly scared.

You absolutely don't need to take two years out for physics. Go to the med interviews, see how you continue feel about it. When you get your A level results, see how you feel and if it's still Physics, look at clearing. Only then, if nothing takes your fancy, take one Gap Year, apply in the Autumn of 25 and start Physics in 26.
Interviews and UCAS forms do not take a year to prepare and submit!

Will I be able to get enough experiences to write a good enough personal statement by then do you think?

Yes, given you don't need any experience for Physics. You need two weekends to read 3 books! Your grades are what get you in to uni, not the additional opportunities you have been able to access.
Medicine requires work experience because it is a vocational degree, heavily subsidised by the tax-payer. Numbers of students accepted is limited, so unis specifically don't want to take on people who don't know what sort of career they are entering, That doesn't apply to physics, or most other degrees and careers.

So do I not need to focus too much on supercurriculars even if I apply to top physics universities? I still want to do some supercurriculars but is it not a be all and end all?