I know it might not work to wear earplugs during band or choir, but there are some out there that are supposed to work for musicians and they will still let you hear but lessen the noise a little bit. And for me I get overstimulated more when there are people too close to me, so maybe it would help to sit with more space around you or sit on the edge so that one side is clear. Or sitting right in the front or right in the back maybe depending on your instrument or place on choir. I think that would be a reasonable accommodation that your teachers could make if it makes sense.

Also i find that self care in other parts of the day can help me like a bubble bath or reading a book. I also use tangle toys when I get overloaded.