I am in my early twenties and although I'm fairly fluent about 70% of the time my stutter is still visible and I do worry about it a lot. What really gets to me is worrying about what colleagues think, people I meet but don't know me personally and if people doubt my abilities because of my stutter. I fret over other things too like dating, meeting people in social situations and things like that. I'm quite accepting of my stutter and won't let it hold me back but I do have my insecurities about it. You're definitely not alone and there's people you can talk to if you feel you are!