How to Deal With Performance Pressure

Diving is like trust: It's very hard to earn, but it's easy to lose. You spend years building up this great muscle memory and then one wrong turn all of a sudden can shatter it. So why is it so hard to just reactivate autopilot? And I've been doing the same dive for two years and all of a suddenly I lose it once. Why do I have to go back to the drawing board?