[quickthrower2]

First off: You are a hero.

Needs to be said.

You are way smarter than most even with the concussion. Way ahead of where I was, using 3 programming languages.

You should find out your full options first then carefully choose. If you can spread your A levels over another year it might reduce the workload and give you time to recuperate. Talk to the school. Changing schools or going to college might be another option if they wont let you.

Apply to Oxbridge still. See if a letter with supporting letters from those involved (school, police)? To show not just extenuating circumstances but that you have solid values.

Is clearing still a thing? You might get in that way too.

Optimise for your health. NHS can be hit and miss so if you suspect the doctors are fobbing you off about something get second and third opinions. If there are issues then consider going private if needed if your parents can afford to.

Good luck… again you are a hero as much as a war veteran, you should get some kind of medal IMO.