Usually this is caused sometimes by such a tight time frame, hostility, disputes between clients, the disaster, either it was a small disaster or a large one, private or public (it occur anywhere, anytime and by anyone), or something else entirely, However.. we really should find a way to be able to anticipate things like this until we can find and return to our own comfort workplace.
What to do?
Be a critical to your own work.. Well.. I don't know.. It is difficult indeed to be able to be very critical to your own work. That's the hardest thing that we usually encounter isn't it?!?! As a designer who also manages designers team, I had the opportunity to test some techniques to work through a slump, beat fatigue, and creative challenges.. but... Not Now!!! I'm not gonna share you all about that this night, next time might be just fine :p I gotta go, I got something to do... Arrivederci :)