Feeling after case study

I’m curious if others have ever experienced this. So I was given a stock to do a case study on and come back with a recommendation. Had 1 week to do it. I ultimately submitted it, but for 5 days straight while working on it, my stress levels were through the roof. It felt really overwhelming and not because I didn’t know how to do the analysis, but what to focus on. I also felt that I really need to impress, regardless of whether I get the job or not, because I’d hate them to judge me otherwise. Anyway, my stress levels were so high and I lost so much sleep over it that I felt super lethargic the following couple days. It reminded me of an exam experience.

Is this normal? Should I use this as a clue that I may struggle on the job with stress if a single case study can affect me so much?