I choose positivity and feel the negativity leaving my body.

It leaves through the body more often than through the mind. You'll be halfway across a car park when a breath goes out that was evidently being held since about eleven, and the shoulders come down half an inch without being asked.

Nothing was resolved in that moment. The situation is identical. What changed is that the body finally got the message that the emergency it had braced for wasn't arriving.

That's a useful order of operations to know about, because it runs the other way too. Unclench the jaw deliberately, breathe out for longer than you breathe in, and the mind quite often follows the body's lead rather than the reverse.