I’ve had some success recently (more for phone calls, but hear me out) when I set my pace in the conversation. Not in the condescending way, “just relax, slow down” that I’m sure we’ve all heard many times. I’ve always pictured speaking to people in interviews, for example, as if it’s a treadmill cranked up way too high and I’m having to jump on and go from zero to full speed. Increasing hesitation and tension that inevitably builds on itself. I set my pace by making my first statement with deliberate pauses and making sure I fit in what I want but not feeling rushed. It makes me feel more confident and on my game, compared to feeling scattered and knocked back on my heels from the beginning. So less a particular technique but something I’ve been working with given a new job that requires a lot of phone calls. Along with stuttering I’ve been dealing with anxiety both with and without medication for a long time, so I feel for you and wish you all the best.