[munificent]

> When I instead choose to ignore the feeling and do the action regardless, it sends a signal to my brain: I’ve chosen to fight.

I think many psychologists would say you did the opposite of ignoring the feeling of anxiety.

> I thought, if my brain is going to flood my body with stress hormones, then it can go right ahead. If I was anxious, then I'd deliver the presentation anxious.

This is exactly what processing and acknowledging a feeling is like.

Avoiding it can take the form of distracting yourself—literally trying not to think about—but it can just as often take the form of arguing with it or "confronting". It's less about avoiding the existence of the feeling and more about avoiding experiencing the feeling. Not avoiding it means acknowledging it, letting it flow through you, and then letting it pass.