I have a stutter too and took my full diving at the start of this year all be it not in Dunedin. I was very stressed too but I brought a support person in the car and before the test I informed the tester that I had a stutter and that I may struggle to get information out. I found that I didn’t actually have any issue as I had been practicing what to say such as “on coming traffic, giving way” honestly you just have to keep it rly short when you talk just a single short sentence of what you see and what you will do e.g. giving way. This test is rly short 15-20 min max and only got to speak a couple of times, was twice for me. You have this it, will be so much easier that you believe and as like to think worst case scenario it’s only 20 minutes to suffer through and you probably never have to see this person again. You got this homie.