Okay, well nerves are an issue for many for sure. It has been discussed before and I have provided links to these discussions down below as well as some other resources that can be quite useful.
Here is a little something that I am currently experimenting with :
Just some main points to begin with
1. As emotion goes up, intelligence seems to go down (so working to control emotion can help)
2. Confidence comes from experience and achievement; as long as you keep going, the "bad" experiences can be just as useful as the "good" ones, so know that when you make the decision to perform you are signing yourself up to gain confidence no matter what,
provided you keep going afterwards.
3. Nothing deals with anxiety like being prepared. As soon as one agrees to a performance, a non-specific anxiety may begin and this can work in our favor if dealt with properly. The earlier stages can serve as a guidance system and ultimately it wants us to succeed. So every time that nervousness arises, make a deal with it to rehearse and prepare. "Okay, I will practice at 9 o' clock" and the anxiety leaves you alone until up until your appointment to practice. Then you practice and it leaves you alone for a while afterward. When it comes back, make another appointment to practice and it leaves you alone again.
Preparation is a key.
Then just before you walk out on stage, 3 steps :
1. Connect to Source (whatever that is for each individual : Parents, God... etc. whatever that is for you) : Simple and silent, heart-felt, "thank you source"
2. Connect to Self : Take in a deep breath and fill yourself completely with your own love.
3. Connect with them (the audience)/ Make it safe for them to be with you there and see you : Open your heart as though it were a light shining from within you and just shine it on everybody in the room, fill the entire room with it.
Chuan C. Chang's book :
Fundamentals of Piano Practice :
https://members.aol.com/cc88m/PianoBook.html is a great resource for this subject, addressing it directly in sections :
1.3.14 - "Preparing for a Performance and Recitals"
1.3.15 - "Origin and Control of Nervousness" - nervousness becomes a problem when it gets out of control.
I would also note that many of his ideas about practice and the preparartion of pieces, memorization, etc., may result for the individual, in a general comfort with the instrument and pieces that can aid in an individual's general sense of confidence entering into a performance situation.
Effortless Mastery by Kenny Werner has also been a great resource for me in dealing with performance anxiety. Hopefully sometime there will be another discussion, in-depth discussion, over the book here on the forum

.
And here are some threads where this issue has been discussed :
https://www.pianoforum.net/smf/index.php/topic,4208.msg39083.html#msg39083(perform a lot in situations that are not stressful and branch out from there - Bernhard- the entire thread is quite helpful and there are many helpful posts from a number of different people)
https://www.pianoforum.net/smf/index.php/topic,4558.msg42811.html#msg42811(interesting ways of dealing with performance pressure)
https://www.pianoforum.net/smf/index.php/topic,479.msg2471.html#msg2471(beta blockers? Every performer deals with nerves)
Sincerely,
m1469