I don't know how else to explain it but often times I'll just muster up a burst of fake confidence. Like if I'm coming up on a word that i know might cause a block I will briefly control my breath, adjust my cadence, then just power through. It's almost like a mind over matter mindset. I know I am capable of saying the word without blocking because I have done it many times before so I internalize that idea and just go for it. Works 99% of the time.