This resonates a lot with how it played out for me. When I first signed up for classes (theory at first, actual driving after the multiple choice exam), it was during one of the really bad stages of anxiety in my life (early 20s, it started when I was 18 after a bad break up). I was able to attend 8 classes in total, but the classroom was always crowded with beautiful looking people, and my anxiety was always off the charts. This one time the teacher was going around the room asking questions and when it was my turn I was very red and shaking a bit, and I could feel everyone's eyes piercing my skull. I stopped going after those 8 classes, which made me feel awful because my dad had already spent like 150€, and it was money he couldn't get back.
Cut to about 6 or 7 years later, years where I'd look at my friends getting their driver's licenses and how freeing it all sounded, and I finally got the guts to simply put my shoes on and sign up at a relatively new school just five minutes away from my house. Two different realities clashed immediately:
Mind: it's gonna be crowded every day, you're gonna be put on the spot constantly, the rooms are gonna be extremely bright and warm, and people will judge you negatively for blushing, stuttering and being nervous. You will fail because it will be overwhelming.
Reality: I had fun every single day, people found me funny and helpful, and theory was easy as hell. I actually looked forward to going every day.
As for the driving classes, I was also afraid. At first I was afraid of making a fool of myself in front of my instructor, and then the perfectionist in me felt guilty for every little mistake (which I allowed myself to let go of by using the rational side of my mind). As the exam date approached, all kinds of terrible scenarios crossed my mind, but somehow I was easily able to use that rational side and think 'wait a minute, you're a good driver, your instructor likes watching you drive, and all you have to do is apply that knowledge and rational confidence for a few extra minutes with someone other than your instructor. How hard can it be?'.
One thing I did was flip the script and look at the anxiety I felt as the day approached as 'nervousness - which is perfectly normal and logical -, not anxiety'. Thing is, anxiety is practicing failure in advance. It's determining the worst possible outcomes and believing them to be real to some extent. Nervousness, on the other hand, is something every single person feels in these situations. This helped me tame the beast. I also focused on being mindful, and thinking and processing one thing at a time. First, check all mirrors, seat belt, etc. Engine on, check if you can start driving, and go.
I even had a situation where I had to park behind another car and I was close to hitting the sidewalk, so I pulled the car back to its initial position and started the maneuvre all over again. Perfect. The person in charge of taking notes of my exam was so confident in my driving after a couple of minutes that she didn't even pay that much attention to it, everyone was just chatting away and talking about all sorts of random things. After about 30 minutes or so, I was done (sometimes when they can tell you're a good driver, they don't even make you do the whole 50 minutes [this is Portugal, you don't have the kind of closed courses like they do in the US, and we drive along with the rest of the world]).
My suggestion to you is: let your mind give you all the worst possible scenarios, but rationally ask yourself if any of they really make sense. Are you that much of a bad driver? Have you proved during your driving classes that you are good at driving when you're relaxed? Then trust yourself, and look at the exam was just another class with a different instructor. Do one thing at a time, and turn anxiety into adrenaline to keep you focused and excited.
