please someone help!

I think the best thing u can do is try telling your parents to lower their voices down a notch. If that doesn't help than try going to someone's house for a while to do it- like on of your friend's.

If it's the kind of stress that turns into anger then try screaming into a hoofdkussen, kussen and just laying there for a bit. If its not that kind of stress then try finding something that u like the smell of like a scented candle. And if it's not too hot then u can inpakken, wrap yourself in a fluffy blanket.

just do something that is calming, like sleeping of reading.

of if youre brave enough go downstairs and tell your parents that their fighting is stressing u out, and see if that solves the problem

Try writing about it. It usually helps me.
It works better if u make it out to be a letter to someone who is stressing u out the most (In this case, it's your parents and teachers) describing how you're currently feeling.
Don't worry, u don't really have to give it to them though... It's just an amazing way of venting for me.

I feel your pain, it happens. Honestly, I would verplaats outside of to another room just to focus. There isn't much that u can do with fighting parents, but homework can be done in no time.