My stutter is very similar, blocks mostly, I hardly ever repeat sounds. Sometimes I can say many sentences without catching a block, that happens when I get into rhythm (speech flows out slowly but smoothly). Meditation is something I do as well, really good for relaxation. One weird thing that happens to me a lot - I get stuck on the last word of a sentence. All the other words flow out nicely, until that last one... Not sure how to fix this, sometimes articulating every sound of a word extremely slowly and clearly helps. One last thing/tip - I find myself blocking much more when I speak quietly (it just happens, I don't notice it every time). Turning up the volume and then once again pronouncing every syllable clearly helps to get over blocks. Thanks and good luck!