You don’t need to work from dawn until dusk every day between submission and the viva in order to get ready.
You don’t need to read and re-read your thesis multiple times. You don’t need to check every paper you’ve cited or considered.
You don’t need to find every typo or amend every clunky sentence. You don’t need to fill the margins of each page with notes and reminders.
You don’t need to scan through lists of questions and worry about what you might be asked.
And you don’t need to be perfect or obsess about now becoming better.
Viva prep helps you get ready for the particular challenge of the viva. It’s a short period of time to reflect, remember and rehearse. The goals are quite small. The need is not so great. You have to prepare, but the work you’ve done so far already carries you a long way.