You’re not the first person to have a viva.
You’re not the first person to feel nervous, anxious, worried or afraid. You’re not the first person to worry that you could or should have done more. You’re not the first PhD candidate to feel you needed more things to go right. You’re not the first candidate to have vague worries or specific concerns about the viva.
You’re also not the first candidate to pass with all of these being true.
You’re not the first person to feel this way but that doesn’t make it any less real or hard. Thankfully it means there are others who will know what it is like to be in your position and be able to help you.
You won’t be the last person to have a viva either – which means that you’ll be able to help others as they get ready to meet their examiners.
Get help now as you need it. Give help later when you can.