It’s not wrong to be nervous about your viva. Expectations and preparations help, but you won’t know exactly what it’s like until you’re there.
You want to succeed and that makes it a challenge, even if you’ve had conversations like this in the past.
You can be nervous, but you can also be ready. How else could you have got to submission and the viva?
You did the work.
You read a lot.
You learned a lot.
You wrote a lot.
You grew and developed and became more than you were when you started your PhD journey.
You know more now than you did at the beginning, not by chance or through osmosis, but through working hard.
You worked hard and that hard work paid off. You wrote your thesis with care, submitted your best effort.
You are not lucky. You are dedicated – you are good enough.
How else could you have got this far?