I always feel like that after an exam. Dont worry i'm sure you did great!
Yeah it was only a mistake, sadly though if she doesn't get back to them soon that F might stay there. So I'm going to hunt her down today.
Even worst is my Adviser get that report that i got an F... and knowing him and how much he already hates me, he's probably in his office right now giggling and looking up my schedule so he can wait outside my class pull me aside and tell me more or less "I told you, you would fail... now what are you going to do dumbass? Your ass is out of here"