Applying for med with achieved grades

I achieved AAA in my a levels and am currently in my first year studying medicine abroad, just started second semester and am thinking of going back.
I would be looking to apply for london unis for medicine for 2025 entry but i would need 1 A* which i think i can get achieve in maths if i retake it right now.
Am i risking my already guaranteed position in a med school? What are the chances i get in for 2025 entry in a london uni? I would be taking the UCAT this summer aswell. Is this too far fetched?

There are very few med schools (if any) that will accept an application from somebody who has started a medicine degree anywhere in the world, unless significant ExCircs - and even then, it is unlikely.
There is also only Kings in London that will accept A level resits.
So chances are very close to zero

How would the universities know i started abroad? I've still got a place at kings for a different degree if all goes wrong. Just wondering as i thought i couldve just said i took a gap year/2 gap years since im going to have to apply in 2024 for 2025 entry. Thanks