I'm towards the end of my ATPL training, and I don't have maths or physics A-Levels. I haven't had any trouble at all during my training so far, but I do know myself that you need to have good common-sense, awareness, and level-headedness if anything. I will say that academic ability is vital to getting through, I've seen many people try and fail who just weren't bright enough to hack it. The old "you need maths and physics to be a pilot" isn't true, but you 110% need your head screwed on.
The ATPL theory exams you take will be the biggest test of your maths and physics. The Principles of Flight exam will be the biggest test of your physics, but it's just a case of remembering rules and applying common sense. This exam is in my experience the one that most people struggle with. Meteorology can be slightly physics-based too, and that always caught a lot of people out. Radio Navigation, General Navigation, Mass and Balance and Flight Planning are more mathematical based, but they're simply a case of remembering formulas, adding, subtracting, multiplying and dividing, all with a calculator and flight computer.
My personal advice is look into how you're going to fund your commercial pilot training before you start making life career choices. Sadly, in this day and age, to be a pilot you're expected to pay every penny of your training, and it's certainly not cheap. Fully-sponsored schemes are pretty-much dead and buried in the UK, as the industry has well and truly shifted towards self-sponsoring. The "I'll join the military and get my licence there for free..." route is nearly non-existent, as militaries are becoming ever smaller, but want to be increasingly elite, so competition is unbelievably fierce.
A sad thing to note with aviation is that a pilot's licence isn't like a driving licence. The "my licence is the same colour as yours" mentality doesn't really work. Airlines want to know where you got your licence, how you got it, and how well you performed in training. You can take the modular route for around £60,000, but you will probably struggle in finding an airline job. You can take the integrated route for around £90,000, and have a much better chance of getting an airline job. Over the years, the big integrated schools (CAE Oxford, L3, and FTE Jerez) have climbed into bed with most airlines, who use them as the main source for their recruits, and to this day the majority of new pilots are sourced from these schools.
Really, you need to know that you have access to around £60,000 before you even think about commercial pilot training. I hate to say it, but it's just the way it is at the moment.