tennisten: "You need to open your eyes a bit. It isn't that some people can't achieve BBC at A Level, but because at that point in their life they didn't necessarily have the opportunity to do so."
By the way, my eyes are wide open to the above. Indeed I fell very much into the above category just a couple of years ago. Was working full time, never stayed on at school, only fairly good Standard Grades (equiv GCSE in Scotland), but nothing spectacular. Was it ever due to a lack of ability? No, it was due to coming from a low income background and never having had the opportunity. So I went back to "school" (while working full time and learning to fly) and did five Highers. Now I have a PPL (like you) and good enough Higher grades to get onto a medical degree (if I wanted to). So it can be done, you've just got to want it badly enough and work hard.