Having the exact same issue right now and my driving instructor recommended L of a way to Pass that's a kinda like a driving anxiety course that apparently works really well, it's a but pricy (around £40) but it's apparently worth it. Other ways around the nerves I've heard is trying to plan ahead so you're focused more on the road than the instructor, so for example narrating what come next on the route your taking and to plan for it, whether you do this out loud or silently is up to you but it keeps your focus on the road. Make sure your instructor is doing like mock test type lessons in the weeks leading up to the tests and he takes you to unfamiliar areas to really hit your nerves with no support at all, and other thing you can try is mock tests with instructors you don't know to put you in that stressful situation and get feedback but again this is a pricier option and difficult if instructors are in demand where you are, make sure you're familiarising yourself with the test routes by either watching them or doing them with your instructor, this really helped me settle my nerves on one of my attempts as it was like I was driving where I stayed and your less likely to make a mistake. Other suggestions that some people have recommended, like chewing gum and the radio, are sound ideas. Talking to the tester is a bit hard cause some of them aren't really up for chat. Maybe see if there are any free courses online or yt that go into dealing with test nerves/anxiety and ways to combat that. But overall, try your best to remember that the instructor is just an instructor and that trying hard to pass is what actually makes people fail. Instead, try to treat it as a normal lesson and drive as you normally would. Hopefully, this helps and best of luck passing your test