Sounds like your speech therapists don’t have training in dysfluency! All of the “techniques” you mentioned are unlikely to help, and can make it worse. If you get fear-based hard silent blocks and depend on word substitutions, you have a covert stutter and should pay attention to professionals who have advanced training *and personal experience* in that specific thing. They exist and many have lots of free info online. The one caveat is the foundation of the work depends on learning to get comfortable with repetitions.