Best of luck with your exams! Trust me, I know what it's like to be under immense pressure to do well. However, most soul-crushing grades that severely damaged my self-esteem ended up as little more than a fraction of my overall grade, even if that was on a final exam or project. Besides, getting one or two bad grades doesn't matter much in the long term.
Even when you do apply to universities, it's mainly the subjects that relate to the course you're taking which matter the most anyway (or so I've heard).
Remember to take breaks every now and then so you don't burn out. Besides having a significant impact on your mental health, burnout also takes quite a toll on your grades.
