I overcame a lifetime stutter at age 70. Mine was the result of unresolved childhood trauma that was finally resolved. I only add that because I had a medium-severe stutter and I know that the only times I didn't stutter is anytime I was discussing my stuttering. It's like admitting it removed the anxiety that I'd stutter and face the embarrassment and judgment. In the speech therapy group, I didn't stutter at all. It's weird but that had nothing to do with the environment at all. Only my fear of disclosure. Good luck, Sue