Well, I guess I ought to be satisfied. Bach went well, having the scores helped a lot. My friend told me that I trembled but you couldn't
hear that I was nervous. Great!

I'm getting worried about my memory. I know my pieces by heart, but when I'm on stage I forget simple things (yet I can handle pretty tricky parts, I'm not afraid of cadenzas, for example). I forgot how the opening chords in Schumann go, so that was rather an embarrassing start. I made mistakes and forgot one place but continued in 1-2 seconds. Otherwise I could handle pretty much everything. What was good was that this time I didn't feel I was about to die, which is usually the case. I did eat a banana, but I don't know if it helped me. Maybe I should eat two next time?

I saw some pictures from me. I had very tense shoulders, looks really stupid.

Hey, I even got flowers. Well, it was actually a cactus.

My boyfriend's father had bought it for me. I freaked out when I first saw him, I didn't know he was coming. He's a professional musician (pianist, conductor, lots of other things), and I'm sort of afraid of him even though he's a sweet man. Another piano teacher came, too (she keeps inviting me to play with her pupils when they have a concert). I'm surprised that I could actually play. I guess I was honoured that they show interest in me.
Wishing you the best! Have a wonderful time playing. If you're having trouble breathing--which I completely understand--try holding one nostril closed and take several LONG, SLOW breaths, all the way to full, with the open side. This should take a few minutes, really stretch it out. Then switch sides. This is calming because it helps you to take in more air, thus more oxygen, which you will want a lot of today.
Isn't that some kind of a yoga exercise? Have you done yoga? I will try this, I only read your post after the concert. Breathing was difficult, I need to work on that.
You can also think about all the nice people who are coming to hear you play, people who are looking for beauty and a little escape. You can give them that, which is a privilege. Also, don't be too afraid about being afraid, if you know what I mean. You can be scared and still play very well... so if you start feeling a little wild, don't think that it will ruin your playing, because it won't at all.
That's such a lovely thing to say! Luckily, I had my friend and boyfriend there to support me. They were the only ones brave enough to sit in the front row. (The piano was very close to the audience, it was a small chamber music hall; yeah, poor listeners... a concerto in a room like that.) My friend always wants to see the hands. She's also very straightforward. If I need to know if I did something funny during the playing, she'll tell me.
As far as playing on concert days, I like to play through my pieces once early in the day, very slowly on fast pieces, and calmly, like each one is a long lullaby. It lets me think through my pieces and their structures in a calm way, and it dissipates some excess energy from my fingers without being tiring. I don't play big, or play at tempo, or play too close to the concert--all those things are too stimulating for me. I do a 3-minute octave and scale warmup a half-hour before the concert, and that's all the real (energized) playing I do the whole day. I also like to see a movie, but only if it's trite and funny, nothing scary or too sad.
I think it's a very good idea to play slowly. I did so, but then I saw my boyfriend's father and rushed into a classroom to practise in tempo. It was a bad move. I think it was part of the reason I blew the opening chords.