What did staying this calm actually cost me?

You learned to hold the line. Numbers do not panic, so you stopped panicking too. Few people manage that. But you do not train one muscle for years without the others going quiet. You did not lose your feeling. You left it unused. What goes unused does not disappear — it waits. You did not build this habit alone, so do not examine it alone. The people on your team have stood near your calm for years. They have noticed things about it you cannot see from inside yourself. Ask them directly what it costs them when you give nothing away. This is not a flaw to confess. It is a trade you likely made without choosing it. Now choose it on purpose. Decide where steadiness still helps the work, and where it has become a wall between you and the people who need to know you are still in there.