Keeping own mental conditon

I'm planning to play the piano on next Saturday in a party. The participants will be 9, including me, and there will be 2 piano players at that date. So, I prepare some pieces for the party, and I usually practice them, once I return to my home. The primary reason why I continue to practice it is to measure my mental condition. In playing the piano with fun, I should be fine according to my experience.
To be worst, I don't feel to play. In such a day, I decide to sleep early, and prepare next day, because everything I do might be meaningless, I feel...

Oooops, time is up. I have to return to my practice today.