It happens to ALL of us, it's how you deal with it that matters.
Things you don't do
* take it out on your horse
* cause a scene in public
* abuse volunteers or event help
* take it out on your friend/spouse/travel partner
(I'm sure there are other examples)
Here's what my friends and I do, we take 5 minutes. Whether it's to go cry/vent in your trailer/the washroom, sit quietly with no one talking to you, punch a haynet in your trailer (if that's your sort of thing), etc.
You don't need to explain why you need to, sometimes that's not obvious to your friends. You just say you're taking 5 or you need 5.
When you come back it's up to you, either calmly talk about what happened or choose not to.
As far as I'm concerned this should apply to daily life too, although sometimes that's tough to do. But really, wouldn't the world be a better place if we all took 5 minutes when we needed to, got it out of our system in private instead of spouting off while emotions are high.