I had the same issue. Anxiety plus my stuttering caused great depression. After 65 years of trying various psychotherapy and speech therapy, I found the right psychologist who dissected my traumatic childhood and at age 70 I became totally fluent. I also was prescribed anti-anxiety medication. There's always that just-right psychologist or speech therapist. There's a breathing technique I've seen that works miracles. It's: YouTube Real Stories StammerSchool. Please watch it, it amazed me. I've posted it in a few r/stutter responses. Good luck, keep trying and keep in touch. Regards, Sue