You are actually super close to the stuff that will help you get past blocks. A block happens bc of an unwanted valsalva maneuver, which leads to core/diaphragm tension. It’s basically a mild panic response from fear of ppl *hearing your repetitions*. The anticipatory fear causes the block. While speaking, Trying to relax your articulation muscles or focusing on breathing is not going to help longterm, and will complicate things. Let ppl hear your repetitions. Practice voluntary repetitions in a mirror, alone. As comfortable, build up to phone calls and in person. When speaking, make eye contact and begin on a normal exhale.