Two Weeks
Thesis done? Submitted?
Take at least two weeks off.
Take two weeks away from reading your thesis, making notes or trying to unpick what all that work has been about. There is plenty of time to prepare for the viva. If you feel like you must do something then check recent journals and stimulate your brain with some new ideas.
You don’t need to keep going with your thesis. In fact, you’ll probably see things with more clarity when you get some distance from your work.