As someone whose stutter was not related to anxiety when I was younger, there are different methodologies that can work to help you avoid your stutter, I personally use "slow and easy speech" (a method I learned at a "speech camp" when I was ~10). When I first started utilizing this method I would think about what I wanted to say, then begin speaking but keep the pace slower than my typical speech pattern. This does make certain situations more stressful, but gets easier with time. Obviously isn't a quick fix, but you will get accustomed to using this speech pattern and it becomes second nature. Disclaimer: as I said this method worked for me. It may not work for everyone, in fact, I know others that needed to go a different route.