You don't have to. But the schools really push you to do clubs, and students feel pressured to do them, because they look good on college applications.
It’s about learning to prioritise, if you can do two extra curricular a per week (say two sports with training sessions) for half the year then maybe a performance for the second half. Split your study’s to two hours per night then you have a good base. Obviously every country is different set ups and individuals are all different but start the year slow and build a solid routine for yourself. You’ll get there I promise
If you get seven hours of homework, you either haven't done past homework, or you have all AP classes.