I get the same way, and if it's really bad, I get a lip twitch. It's a speech block. If I'm stressed or anxious, it's very strong. If it's with family, like I have to tell them something important that makes me nervous, I remind them that I may have difficulty speaking. I've stuttered since I could speak, so they know what to expect. I have worked really hard to learn to relax my facial muscles, back and shoulders. This tends to help my voice box relax. Secondly, before I need to speak in public or to someone important, I go with a stoic strategy: I tell myself to worry about it later. I keep my head clear, my body loose. If my brain veers toward worry and anxiety, I think about something else - ANYTHING else. It tends to help!