Certainly having a grounding in maths and science can't do any harm. Your lack of education will not help when it comes to the ATPL exams and it must be said, quite a lot of the practical flying.
However if you can overcome that, it won't really impact your career as a pilot because what actually counts is your licences and ratings. Potential employers really have little interest in your school exams.
Despite what people think there are no actual educational requirements for pilots unless going into the military. But you do really need to have some form of foundation if you're going to get through the training.
As for your Engish, that is tested now as per ICAO rules and noted on your licence. If you pass all your exams and flying in English. That's a pretty good indication of your proficiency.