Answer:
Try retaking tests, if you can.
Explanation:
The only way to help your grades is if you retake tests or quizzes. If you can. I know stress can be a pain, but the only way to help relieve your stress is by doing things that are calming. For me I listen to music, read, write, and sometimes draw, but it's important to do what you like to do. Maybe if you take a break and do something fun and clear your head then you might be able to think through things better. I hope that this helped.<3