What makes you ridiculously angry about the college admissions process?

I’m mad that I’ve worked hard and done well for years. Signed up for a college class being taught in our highschool but I was absent for the exam and now the lady is giving me a D with no chance to make it up. So all a’s and now I have a d. I don’t know what to do. She is refusing to give me a chance to take it. Even with a doctors note and everything.