My stutter is blocks as well. It's much easier said than done I know, but when you get into a block, try and just stop. If you try and push the sound too much you might develop twitches which will be 1. more embarassing, and 2. potentially painful. Trying to get words out in one full exhale is the actual answer, it's just hard for us to do. The best I can recommend is that you keep practicing speaking in an exhale. If you get into a block, stop, and try the word again in an exhale. It may take you multiple tries to finally get the word out, but I see it as much more effective than pushing through a block. Here's another word of advice that took me years to realize - don't think too much about the word you're stuck on - think about the next word, and the word after that. You'll start to remove the subconscious pressure off of the word you're stuck on, and it becomes easy to say. This realization helped me a lot. Same with reading, look at the next word, not the one you're saying. I hope this helps you or anyone else.