I hear ya. it's probably something that too hard to do right now. Vowels are super hard to let yourself stutter on, even if you want to. Im in a new therapy program now and I still cant let myself just get on that vowel sound and move through it. Eventually i'll be able to "bust" right through on the vowel but yeah im still trying to get a hold of it. I'll try to come back with some advice later if I come up with anything. But I do want to say that just hanging in there, on the sound. Even if it's blocked is progress if you used to do any tricks to escape before. the longer you can hang on the sound and just sit there, even if you still feel fear, the better your developing your tolerance to these scary/terrible feeling situations. On the phone, this might not be the most practical but I do admire your courage in trying to keep with it.