Everybody in the world has blocks they don’t attach significant meaning to it and they don’t get in their head before speaking (did u see Carey price recently at the nhl draft??). Try speaking to your stuttering subconscious by giving it a name and talk to it as if it were friend - what would u say to ur friend who stuttered? You’d probably laugh together and go ‘Oop, technical difficulty! Let’s ignore it then and go have fun!’ Try that for a few months.