Tired of school 😞

I'm currently struggling with two of my classes because there seems to be an issue with the grading in my social studies class, and my math teacher hasn't resolved the grading issue despite saying he would. I'm concerned about failing 8th grade, especially since I consistently complete all my assignments, but sometimes receive failing grades on work I know I've done correctly. I'm feeling really discouraged about school right now. What steps should I take to address these issues?