Same Postiton
I'm in exactly the same position as you year 11, wannabe airline pilot and a couple of flying lessons under the belt. The careers advice woman and some reserching online also contacting airlines to ask what kind of things they look for in a prospective candidates education suggests, finish school (get good grades). Then go and get A levels if you fail the medical you you have a qualification to fall back on. Preferably studying Maths, English and physics. Apparently they look good even if you fail.
Then look to flying schools both self funded and sponsored by airlines although becoming more and more scarce. Many flying schools offer financial aid. London University offer an aviation course that gives an ATPL and a degree in aviation management. Then when you have an ATPL offer your services for free to parachute schools for instance or glider clubs.
Also when looking at sponsorship a good way to show that you are truely enthusiastic about flying is to have self payed yourself through a PPL course. Hope i'll see you in the skies some day, good luck.