Math grades ruined by anxiety and lack of sleep.

[prererr668]

Currently in a high school calculus course and a precalc course. I am prepping for exams, but I already can't think properly due to test/ grades related stress. Grades were initially going well (95+) and then I got a few bad tests back and haven't been able to make a recovery since. Thoughts on trying to avoid/ mitigate this stress induced brain fog + tiredness?