I have similar feelings. I feel shame around my almost covert stutter. there are fluent days and there are difficult days. When I was younger, alcohol and drugs helped me a lot to get comfortable in social settings. But as I get older, I almost care less if I stutter or what people think. Being able to be vulnerable front of others is the first step to be able to relax. I just had a presentation which I stuttered through, but I felt accomplished because I was brave enough to do it. And at the end of the day, nobody cared about my stutter just about my presentation. Plus I’ve started dating someone who to my surprise, absolutely adores my stutter. Haha so that also makes me feel more comfortable with myself. I would like to know what technique people use apart from substituting words. Like how do you relax?