School is killing me

So I'm a freshman in high school and I get so stressed out. My grades are eh I have 2 Bs and 2 Cs and even though I spend 2-4 hours working  on homework everyday. For example, English. I am in a honors class and I have a C in the class which is horrible 😳 or in history which is also a C and I'm currently doing 3 extra credit projects all at once. I still have 2 Bs in my other classes though.  My mom thinks I should also do extra credit for science but I don't want to. 😅