Hey there,
Have you tried talking to some teachers at school about what you're going through? They may be able to help you with your situation and even with talking to your mum about online school if you really need it.
But for the time being, try finding something that can help you distract yourself. A hobby or maybe just hanging out with a friend can help you relieve the stress that you're experiencing from school.
Feel free to
PM me if you ever need anything!