I recently realized, that my blocks were actually due to me resisting my authentic stutter. My real stutter. The more I resisted stuttering, the harder the blocks. Blocks being when you try to force it out with all your power, trying not to repeat sounds (stutter). I blocked my whole life, and I still do occasionally. But once I decided to stutter "authentically" or "unfiltered", the blocks didn't happen anymore. But, this did mean I would repeat words/syllables wayyyy more. This is what I call my 'authentic stutter'. I blocked my whole life, because I absolutely hate(d) my stutter to my core. I absolutely didn't allow myself to repeat at all. I would rather block, then repeat. It would always make me dizzy, headache, sore throat, loaded feeling in throat, etc. I still block occasionally, but not as much. It usually happens when my speaking fear gets the best of me in certain public situations and I forget my techniques. Maybe this helps your, too. Good luck!