How is this possible?

i'm going to be a senior in high school next year and yet i don’t know how to write a essay and i can't do algebra. I don't know much about nouns and verbs, and ect... i can't write/read cursive and I couldn‘t even tell you anything about science, how did i make it this far? what am i going to do when i get to college? Is it my fault or the school’s fault?