Speech pathology student here! Stuttering usually presents in three different ways: blocking, repetitions, and prolongations. Repetitions are what people usually think about when someone describes stuttering. For example: "p-p-p-p-popcorn." Prolongations involve drawing out sounds in a word, like the "aw" sound in "pooooopcorn." Finally, a block sounds like what you described in your post, where a person struggles to get sounds out, like "p---opcorn." If you live near a university with a speech pathology program, almost all of those programs provide discounted services for people interested in getting therapy! I encourage you to look into that kind of resource if it's available and if you were looking for some kind of professional support. My university also has a stuttering support group, which I've attended a few times (although I don't stutter, I just went to check it out) - it was awesome! :) Let me know if you'd like more info!