Hey! Glad you like it :) I want to point that I've done little scientific research about stuttering, so take my answer with a pinch of salt. I don't think it's all in our heads, there is some genetic clues that point there is something "somatic" about it (inheritance, studies showing certain differences between stutter and non stutterers)... However I do think there is little known about it; which I kind of understand, there are a lot of different patterns of stuttering, triggered by different things, it may get better randomly... it's not exactly the dream group to do trials and extract conclusions; there are too many variables, and probably some of them gets overlooked. The head thing however make it way worse because most stutters have to deal with "microagressions" daily, have trouble standing by themselves verbaly, are pictured in the collective imaginery as fools/cowardly/inept people (just take a look to most stutterers in films and books)... And treating the stutter is "optional" and in very rare cases the psychological part is taking in count until the person is dealing with some serious mental problems. All this make stuttering way worse and severely affect the quality of life of stuttering people. It gets more complicated when you include in the ecuation other kind of stutterings and thins that resemble it (stuttering for brain damage or asociated with some syndroms, stumbling -think of Hugh Grant-...) About your case... I think my stuttering is kind of like yours, confidence (and in my case also anger, so go ahead and tease me XD) boost my fluency (and most stutters don't get stuck when alone or just animals); but an stutter is an stutter and denying it will backfire. If you gets randomly stuck and it gets better and worse, you have it; if it happens it's unfortunatelly not in your head. This doesn't mean it'll stick with you all your life, some stuttering go away or reduce it to a non-noticeable point when the person grows up but you could develop a cronic stutter like most users in this subreddit. I'm not sure about the age tho, if I recall right, most stutters develop it earlier (kind of 2 to 6). Mine was at 5 YO for example. And about it being triggered by anxiety or stress in your particular case... no idea, it could make sense or you might have developed it later... that's very hard to diagnose in general and I don't have the qualifications or knowledge to find that out, sorry :(. But being practical: If those "supplements" that are helping you are all legal and are not harming you in any way, then I see no reason to stop taking them. However, in case you are not already, I do think you should get theraphy (both speech and psychological) ASAP to have the best shot to make it fade away or learning to live with it. And it's a long shot but I'd recommend you to check it also with your doctor or a neurologist, a late developed stuttering will be nothing most of the time, but it could be mean things. Best of luck!