I can relate because I feel the exact same pain but I couldn't find anything online about stuttering actually causing physical pain. Atleast you could give presentations. I never could, and the few times I tried it just made my stutter worse and I started stuttering even when talking normally to the people I was comfortable with. Now I've just stopped giving presentations because it has gotten so much worse that whenever I am asked to give a presentation and the deadline is approaching my blood pressure rises to dangerously high levels. On the day of the presentation I get nosebleeds and feel lightheaded. I don't know if not giving presentations is the solution but I don't know what else to do and this is the only way to keep my blood pressure under control. (I do not have hypertension)