Maybe fear of stuttering wasn't the best term. Maybe fear of unrestricted stuttering or fear of "too ugly" stuttering. I sometimes have very strong blocks. Only a few times have I absolutely not been able to get a word out. And this is after like 3-5 minutes of trying to just get the first sound in. But most of the time I just try to focus on making noise on that first sound, getting any noise in at all. It can take a long time and most of the times I try to stick it out, i'm talking to a friend or someone who I know will wait. Honestly, if im talking to a stranger and I know it wont come out (this is usually comes after at least two complete minutes of working on that sound), i'll just use whatever tricks I can to help make it easier. Anything from using "ums" to running starts or putting a different sound before the word. I avoid tricks most of the time but it's not worth having a stuttering meltdown over.