I’m a PhD student in a physics program and the only advice I can really give is to just be confident in yourself. Your stutter makes you unique and gives you unique insight into your work, and accepting this has been the biggest thing to help me in grad school. Stuttering during a presentation might be awkward but don’t apologize for it or anything, just keep going. I’ve given award winning presentations and I don’t think my stutter held me back at all. I know it’s really hard to be confident when you’re stuttering all the time, but understand that this just takes time. It’s a matter of changing your self image, and making yourself truly believe that you’re just as good as everybody else there. You got to where you are because of your own hard work and achievements, your stutter will only hold you back in an academic environment if you let it control you.