Tell me about these intense situations? What goes through your mind before you're about to stutter? Are there times where you're fluent? Are you perhaps fluent when you're speaking to yourself? If you answer yes then there is no problem. If you're able to speak fluently in one context you can speak fluently in all contexts. It's your mind that has created this grotesque horror film about stuttering that prevents you from being able to speak fluently in certain contexts. Think about it, when you're about to speak to someone and you know you're going to block think about the movie in your mind? The image you see of yourself having an upcoming conversation with someone. What does the movie look like? Tell me about the qualities of the picture? These images and internal language are what creates the intense state of fear and thus the state of blocking. You almost fear the fear right? There is a solution!