Teenagers do not deserve so much pressure over their GCSE results which are used by politicians to bully their teachers.
There are many other important things in which young people should take an interest: work (illegally If necessary) travel, volunteer and looking for other worthwhile things to absorb their time and energy.
Failure at sixteen is never the end of the world. I failed English literature at sixteen but, twenty years later, I was an examiner for the subject.
ps. If your teachers complain about your behaviour ask why they keep you in school.