I think for us stress does make it worse. Not that the stutter originates from stress, I mean I genuinely don't know and feel like we may never know but I know it's come on randomly for me, but if you can not care what people think and just focus on the message you're trying to say, self consciousness aside and if you stutter just take it easy and let it be, that helped me immensely. As I stuttering I knew the stutter would go away it was just a matter of time. I didn't know how or why and when but I knew I break out of it and it was usually not in an impractical amount of time, like I wouldn't be caught on a word for 20 minutes. But if I worried I'd get caught on the next word and the one after and even though it wasn't one word for 20 minutes, it would feel like 20 minutes worth of it. So by relaxing and letting it be and not stressing on how I must look, the stutter comes, it goes, and fluency came and eventually I came to this state where I just don't stutter or barely do now and hardly notice or if I do, I don't remember it because I choose not to. It happens, nothing I can do, so why remember and stress over it, I always think of something else now.