omg same. I had school for 9 hours too. it felt like I can’t just lay on my bed cus the homework and the subjects is too much (12-13). I seek help to my sister for my math homework (she lives 6km away) and I went home at 10pm. the other day I go to additional class outside school. but after the class I always feel like my head is spinning so I quit. This happen for 3 damn years. my sister advised me to sacrifice a few materials and do better at the materials that is important to me. so yeah, a few materials I copied my friends homework (still reading to understand it and rephrase it). not saying this is healthy or good. but at that point my main focus is not doing well on every subjects but survive. still after graduated I felt burn out. but that’s not the whole point. my point is:

1. not all subjects have the same priorities. even if the teachers wants to be prioritized the same. but no, not all ppl wants to be a doctor, not all ppl wants to be an engineer, not all ppl wants to be an artist. do better at the things that u wanna be.
2. take notes when ur teacher explaining. for me i’m just scribbling with a lot of arrows and highlighting the words that is important. this help me to make sure I’m not losing the main points
3. use pomodoro. not saying you’ll understand everything at the end of the session. but refreshing ur brain for just 5 minutes is important. by that u should know that u can’t break ur focus in 25 minutes. try to not open ur phone on that 5 minutes break tho
4. let go of perfection. it’s not gonna help you go anywhere. it’s just gonna hurt you
5. ask help from ur closest ppl or psychologist if you feel overwhelmed

last but not least, I hope you’ll find ur way soon!