There’s no rush necessary in your viva preparations or in the viva UNLESS you make it that way.
Fail to think through what you need to do and you might make things pressured. Fail to prepare for how you’ll act on the day and you can feel that you need to blurt out answers and not think when you engage with your examiners. You don’t need to rush unless you create a situation where that’s the only thing left that you can do.
You have the responsibility, no-one else, but it doesn’t take a lot to live up to that responsibility.
Plan the weeks leading up to the viva. This doesn’t have to be hour-by-hour, just think about the kinds of tasks you’ll do and when you might do them. You can’t plan for every minute of the viva, but you can think about how you will react. Think about being in there. Think about being asked questions. Think about how you might respond.
And think about how, unhurried, you can present your best and most confident self on the day.