Trained Conservatoire performance artist with not only a speech impairment, but spasms and a wheelchair checking in! Just go up and do it. There's no secret to these things, there's no magic bullet that'll make it easy and yeah, you might end up stuck. But, if you do - take a breath, and start the word again. What makes a performance good isn't always about technicality and being normative in speech patterns and physicality, what makes a performance good is when someone gets up, and commits to doing the thing. Not when someone pretends to be something else, not when someone has apologised for being 'different' with their body language, and their mentality - its when you get up, and do the thing. You stutter, cool. That doesn't make you incapable, all it means is that you stutter and your performativity is different than some other persons, but everyone's performativity is different from everyone else's. Only real difference here is we - as a society - have made stuttering A Thing. What helped, and helps me is deciding that no, its not a big deal, its just how I talk. Just go up and do it, you're perfectly capable and your stutter doesn't change that capability, it just might inform the nature of that capability and that's fine. You're good, and if you stutter, so be it - if you get stuck, okay. Breath, continue. It's fine.