Hyped
It’s sometimes said that excitement and nervousness are two sides of the same coin.
That might suggest there’s no control over which side is shown, like a coin toss, but really it’s just focus. If you try to focus on excitement that’s what you’ll find more and more.
You could focus on the opportunity to talk about your work with experienced academics. You could think about the contribution you’ve made to your discipline. You could think about how close you are to finishing your PhD!
It won’t eliminate nerves, but getting excited can help a lot to reduce the discomfort of nervousness – and maybe it will give you one more reason to feel confident for your viva.