Noting Genghis's response and your own, it seems clear:
A-Levels are the option that you (more) want to do.
Yes - it will be very difficult, but if you can not see yourself doing anything else - there is no other option aside from guaranteed financial ruin, that will suit you and your needs.
I do not know how much you know about / have looked into A-Levels - but if you do plan on self-study - ensure your college (where you are hoping to take Mathematics) will also allow you to take the Physics exams / coursework at their premises - unfortunately with Physics the coursework may make self-study more difficult as you require observation of your coursework practices so that no 'cheating' has been allowed.
Having said that - it is possible to pass the Physics A-Level with no coursework being done and solely relying on examination passes - but you would not be able to get an A* in this case I believe. (If that matters to you).
(At-least I think it was that way when I studied it!). (As an aside, the Government are changing the requirements of A-Levels I have heard - so this may / may not be applicable to you - be sure you know what you are signing up for!).
Regarding the learning to fly / working / studying - it will be difficult, but not impossible. As with everything - there will be times when you want to give up, throw in the towel etc. Yet if you just remember why you started the process and what your end goal is - continuation should be the obvious option and solution.