Viva preparation helps you to change focus from the kind of work needed to get you to submission to the work needed to get you through the viva.
Is it ready, how much more, did I tweak that change that get it right…
Rush and overtime, a few more days, got to get it done get it done get it done done done
Prep, and the viva, require a slower pace. Nerves or anxiety come from the viva being important: rushing, continuing to try and get everything “right” is only going to compound nerves.
Use your viva prep time to change your focus. Slow down. Take your time. Read your thesis, make some notes, practise a little, remind yourself of your accomplishments and abilities.
Change your focus from rush to ready.