This is very very common textbook blocking. You block bc you are so ashamed for others to hear your repetitions, that you force so hard to get the words out, your vocal chords literally clamp shut. Here’s how to block less - let others hear your repetitions, practice first alone in a mirror. Build up to phone calls thrn in person Whrn talking, make eye contact, and begin on an exhale, and begin slowly and enunciate.