You have some interesting insights and have clearly done a ton of work! Also, I’d like you and others to know there are SLPs who specialize in dysfluency who have helped many people become more comfortable/fluent. Many are also PWS, but you’d never know. These are the things that have a track record of helping ppl drastically and sustainably decrease blocks, avoidance behaviors/fear, and speak comfortably and smoothly: Don’t go out of your way to replay/analyze/document your unpleasant episodes if it’s causing anxiety, as this reinforces the fear. Instead, allow others to hear your repetitions. Practice in a mirror, doing voluntary repetitions, and watch yourself. Build up to voluntary repetitions on phone, and in person. Before starting to speak, make normal eye contact. Begin speaking on an exhale, (not inhale), and begin slowly. Enunciate, using regular/interesting/appropriate tone, cadence, timing and volume.