I was in the same boat last year! My first time playing for my studio class, I had to perform the Chopin Op 48 #1, and Debussy 'le vent dans la plaine' and 'collines d'anacapri'. Each of those are pretty short, but they have some damn tough little measures!! My pedal foot shaky, my hands were mush, and I was disoriented

Right after, I had to page turn for 3 sets of variations of 'the people united will never be defeated', that another student was playing! (I'd say I was more nervous for page turning lol).
My jury was ok, but I had the same issue!
This year, I made sure I got an opportunity to play in studio every week, and would openly accept criticism from students, and I would discuss after playing what I found tough/what I did well playing. This helped alot to situate myself when I play. I got over the idea that I am 'being judged by everyone' when I play, and accepted that they WANT to hear me play, and no matter what will have something (positive or constructive) to say. From this, I'd kind of tell myself "play the damn piece!".
On my jury this year, my final piece was the Mephisto Waltz. It wasn't the coda that bugged me, it was those awful accel. chromatic runs in the first few minutes of the piece. My issue all year was that I'd speed up at the start, and then flub those. Several times playing it in studio, I'd completely mush up my right hand and butcher that part because of my nerves making me speed up WAY too much going into it. Once I got more used to being in a relaxed state starting the piece, I really could do whatever I wanted while playing the piece (and not go on freakout automatic pilot, and inevitably speed up); once I got to that passage on my jury, I was able to prepare myself going into it, and adjust if I needed to.
My biggest issue when I was growing up was paying a piece by muscle memory (I've always been able to sight read well, and I would kind of force the notes down quickly and memorize it, and ignore a lot of the detail until right before an exam... and then have to pretty much memorize the dynamics separately rather than naturally include them while playing). When a technical part would come up, I wouldn't even know I was going too quickly, and would have an "oh f*ck" moment and just blast through it.
Let yourself know that whoever you are playing for is grateful that you are about to create awesome music for them to listen to (even if it's an old examiner). If you are comfortable playing a difficult part on your own, remind yourself "now I get to play this for someone else" rather than "damn, I'm going to screw this up in front of this person". Nerves make it easy to think negatively, but really try to allow yourself to think how you want going into a performance.
If you barely know the piece though, and are going to perform it, I don't know what will help you

. A lot of people will get nervous if they simply aren't ready to play the piece technically.