Who do you know who could help you get ready for your viva?
Your supervisors can help with a lot: setting expectations, hosting mock vivas, sharing ideas of what examiners do – there’s a wealth of support from them potentially.
Departmental friends and colleagues around you understand: they may have first-hand experience of the viva, they could listen to what’s bothering you or even be a part of discussions to help you practise.
Family and friends might not understand: they can still help you by providing a space that you can prepare in, or by giving you time to do the relatively small work involved in preparation.
No person is an island. You don’t have to do everything alone. You might be doing the most work, but others can help lighten the load, in lots of different ways. Ask your community. Perhaps ask early to help set their expectations and schedule support, but know that there are lots of people in your life who can make a difference as you prepare for your viva.