One simple quick fix: breathe.
It sounds ridiculously easy, because it is. Your lungs are your body’s tool for regulating the rhythm of everything.
Think about it. Your heart, your nerves, your digestion, all depend in some way on how quickly you are breathing, and if you are stressed, these processes can start happening much faster than necessary.
When you feel like a speeding train heading for a cliff, just step back from whatever you’re doing, breathe deeply, and count to ten. The rest of your body will follow accordingly.