I think the best way to not give a fuck about what people think is to just own it. You have a stutter, it is what it is. It doesn't define you, it's just something you have. Instead of being afraid of it, just own it. They're going to hear you stutter, you can tell them you have a stutter, and if you're confident about it, no one will even let it phase them because YOU'RE not letting it phase YOU. I know that's hard to do - and it does take practice, but that has been the one thing that has truly helped me. It doesn't help the stutter itself, because not many things will, but it does help how I handle it, and I do notice I stutter less the more confident I feel.