Here are some things that worked for me, but realizing too that everyone is different. Hopefully, you have had a chance to try out the instrument and hall beforehand and have a familiarity with the venue. Bear in mind that when there is an audience, the hall will not be as "alive" as when you performed there by yourself in an empty space. That's fine, as you will be your own best listener there, and can project and modify the pedaling as needed.
First, get a good night's rest the night before. On the day of the recital don't do anything out of the ordinary or strenuous. Just follow an easy-going routine. When it comes to your normal practice time, do only a sufficient technical warm-up, no more. Do a run-through of your program. If you encounter a rough spot or two, calmly work them out using the same thoughtful practice method for those difficulties that have worked previously for you to smooth them out. Do not do maniacal practice, as it will do more harm than good at this point. Then do a second run-through to further build confidence. Then leave the piano. As the day wears on have fairly light meals. Later, if you want to kick off your shoes and take a short nap, do it.
If you can take a taxi or have a friend drive you to the hall, so much the better. Get situated in the green room if there is one, or in a wing backstage. If there is a remote piano, do no more than playing two or three scales, then leave it. Do not do any "practicing" on a table, on your knees, or even in your head. No need to--you know this music. Make sure that a copy of your program has been placed inconspicuously on the piano's closed music desk. If the desk has been removed, have it by your station backstage so that you can quickly review the order at the break segments. In the excitement, people have been known to forget the order of pieces. Having the program at hand will give you security even if you don't have to refer to it.
When the moment of truth comes, stride onto the stage and smile at the audience to acknowledge their welcoming applause. Sit down and take a moment to ensure that the position and height of the bench are as you want them. Do any minor adjustments as the chatter and coughing subsides. Then sit for a moment collecting yourself and dwelling on the mood of the first piece. Prepare mentally for the start, e.g., will the damper pedal already be depressed before the first note? Get ready to do it. Wait for total silence. Then begin. If you're as prepared as you should be, you'll then be in the service of Chopin, an awesome responsibility indeed. You'll be into the joy sharing your interpretational insights and connecting with the audience. That responsibility is equally great in presenting your own works. It is not every day that an audience gets to hear a definitive performance of new works directly by the composer, which then sets the performance practice for the future. You did not mention encores, but you should have one or two picked out and prepared to the same degree of perfection as the program itself. Do the larger one first and the lighter one as the close. Good luck!