I often wonder this too. When I'm at home and with family and friends I rarely stutter. If I'm in a situation where I am expecting a question or someone to talk to me my stutter is still there but much less profound. It's when I'm not expecting people to talk to me is when I get anxious and my stutter is worse. I believe the social anxiety is the cause of my stutter. I'm thinking of seeing someone about my anxiety. Maybe that would work for you too ?