what a mess

A: What's up, Carla?
B: Oh, don't mess with me, now, Loren.
A: Whoa! Looks like somebody woke up on the wrong side of the bed. What happened?
B: I have had a really lousy day.
A: Come on, tell me.
B: I've worked my head off to finish my project. Only to be rejected in the end.
A: That's too bad. Why?
B: I submitted the wrong papers.