In my senior year I took the Fundamental Engineer Exam (FEE) with a focus on Environmental Engineering at the end.
Definitely walked out of there saying, "Well that was a complete and utter failure." Got the letter in the mail a while later saying I passed. I was 100% stunned. I studied and prepped for it as best I could, but always thought I could do more. While taking it I was so stressed, and when I was done I was almost positive I failed miserably. Guess not!
You probably did just fine