Someone will tell you, at some point, that you handled that well — the phone call, the diagnosis, the room full of people. Your instinct will be to correct them, because you know exactly what the inside of it felt like.
Don't be in a hurry to. What they saw was real. They watched the version of you that stayed in the chair and asked a second question, and that version isn't a costume. It's the part of you that did the actual work.
Fearlessness, seen from outside, is mostly just somebody who kept going while afraid.