This sounds like something I would have found really challenging a few years ago. What really helped for me is just admitting it, right off the bat, that I have a bit of a stammer. Boom, sets expectations in the room and comforts you as people won;t be looking at you funny. In my experience, most people find otyher people with stammers endearing, as its seen as an honest, open trait. I appreciate that standing up in front of everyone and saying 'i have a stammer' may seem daunting, or even defeatest, but I;ve been doing it for years now and have never had anyone laugh or deride me for it, plus it's really improved my speaking. Good luck!