I´m sensitive to persons too. Senstive in general. Like a dog catch me by surprise and I jump like crazy hehe. I think my nervous system is constantly on a sympathetic mode because of the constant worrying and anticipation because of my stuttering. I can notice pretty easy when the other people is getting upset or angry and I feel very uncomfortable. Whenever I have a good night sleep or after a gym sesion I feel more calm and less sensitive to my enviroment. If only I would be rest and stress free all day long every day I would diminish my stuttering at least by 50%. Good observation.