Agree with the all the above. I doubt the pressure ever elevates, I imagine you just learn how to handle it
Proper planning.
Plan where you need to be, when you need to be. So when you get into the car, you know where to go, give yourself enough time to get there. Make sure the sat nav post code is the right post code….often it's not, or not the entrance.
Know the heart beat of a wedding, of the routine, expect THE shots, the kiss, the tears.
Back up, back up, back up. Prepare for if camera break, if memory corrupt, dead battery, dead lens, flash heads. Do you know what really helps. Put a prime on your body and go away on holiday and use that and only that for a week, no flash, no tripod, and use it to take photos of everything from your view, the food, the sights, the street, the people. You will learn to think outside the box within a box, you will learn a focal length, you will learn the lens, you will learn the limits of both what the gear can do and also what you can do with the gear. It's an experience that will exchange your skills in a way that let you know how far you can push yourself with what you have in your hand.
So imagine if everything in your bag breaks and you end up with just 1 camera and 1 lens….what can you do with it?
Drink plenty of water, breath, deep breaths, rubber soles (leather makes an awful noise), wear something appropriate (not a T-shirt!), have right insurance,
Smile!