If you’re working towards your viva now you are so close to being finished. And to get this far you’ve already successfully completed many major milestones. Some you will share with other candidates, they’re part of the general PhD journey; some will be your own, and no-one else will have had to rise to the challenges that you have.
If you’re nervous, concerned or afraid then at least remember that you are good. You can do this. Don’t forget how far you have come. Don’t forget how you have succeeded despite living through strange and challenging times. You’re so close. You can do this. Keep going.