Missing A Whole Test - ArghhhhhhhFADFSASD

Okay, this is unacceptable. I took a 24-hour test online and missed a whole pdf worth of questions. When I got the test, I saw the note where there are only four possibilities of scores. The scores are given out to the exact fourths of a percentage: only 0, 25, 50, 75, 100. I immediately related it to a four-part question. I opened up the test pdf and saw a four-part question. And somehow, I related that to an immediate one question test. I mean it was a Friday, and online classes mean that I do not have to "go to school" nor zoom meetings. My immediate understanding of how it's one question with four parts made me not scroll down or me aware of the number of pages in the pdf. I ended up doing only one question. The tricks that were involved with the first question made me think that it is worthy of a one-question test on a "non-school day". And in the end, I suffered the consequence of being stupid and got a 20. What the hell. I thought it was a one-question test and went with it for around 3 weeks now, never noticing it. It was when I saw the 20% grade that I just paused, breathed, and dropped my head onto the hands that are helpless on the table. I have lost all hope for myself and gained tremendous disappointment. I have nothing to say but create the sense that "I hate myself". I am just curious to how did I manage such extraordinary feet.