I didn't have the qualifications and got through as a serving airman. In those days there were MANY more training slots available. Even then, although I didn't have the O Levels, they required some sort of equivalent educational qualifications. My Avionics training involved a lot of maths, this was seen as acceptable.
Now the negative bit.......... Although I agree that you should always TRY to achieve your dreams, please be realistic. Even if you are the modern day 'Chuck Yeager', you are up against some highly qualified, sharp candidates in the selection process. The recruiters will be looking to you to stand out from the crowd in other ways. ATC membership is almost expected these days, so what will help????
Sport/Charity+Community Work/GOOD DEPTH of current affairs knowledge/Fitness Level/Appearance and more.
Have you considered other flying trades?? Non commissioned aircrew often get pilot crossovers when they are slightly over the age limits.
Be flexible, you don't have to be a pilot to enjoy the lifestyle........