No, you won’t need a box of tissues. We’re talking about one particular emotion that boosts your credibility. It's this particular desire: I want you to understand what I'm talking about. You have to want that, and you have to show the audience that you want it.
Feeling stressed by the thought of presenting? Heart beating faster? Sweaty brow? Clammy hands? Short of breath? Wobbling kneecaps? You're definitely not the only one to suffer such symptoms. The vagus nerve squeeze not only deals to those symptoms, you actually feel calmer immediately.
Just one caution: if you overdo it, you'll faint.