Read the article in link below and practice «flexible rate». I have done it for a little while and it really helps me when i have a Block and I have actually started getting confidence in speaking. I have practiced A LOT in every conversations every day. I hope this can help you to. From your description I had the exact same pattern in my stuttering, but for the last couple of days I have actually been able to say what I want when I want with «easy stuttering» instead of complete blocks. Read up on «flexible rate» and try to allways speak slow and with a relaxed abdomen. Read this link, and the other articles from University of Minnesota: https://ahn.mnsu.edu/services-and-centers/center-for-communication-sciences-and-disorders/services/stuttering/information-about-stuttering/serious-information/viewing-stuttering-holistically/essays-on-stuttering/and-the-stuttering-just-dies/