I relate to this a lot. I recently graduated college and have been working full time for over a year now. Work is going great and my boss has complimented many times on how I exceeded expectations for the first year. But still even with that, my stutter goes in vicious cycles. I work in insurance sales so ironically most of my job is on the phone talking to people. And 95% of the time I am fluent. There is just that 5% where I can not even talk and just simply cannot say words (it’s the same words too, every time). And I let that 5% of the time drag me down and it feels like I will never fully reach my full potential because I will never sound as “smooth” as other people. So I can relate to you a lot on that part of not reaching potential.