Another service started in a few minutes, and I didn't know what to do. It's not preaching if there is no active faith at work. Preaching is, by definition, an act of faith. Feeling vulnerable is part of the package, but part of preparation, as surely as exegesis and outlining, is activating our faith that God will work through this message by his Spirit. Confidence comes from outside us.
Preachers can traffic too much in the realm of personal musings.
Such thoughts may be theologically solid and pastorally wise, but it's the Word that is our power. Our task is to let God speak for God. Preaching is not for the faint of heart. When I forget that, I start sinking, wide-eyed, into the waves of doubt. When I remember, I can walk on water.