If you're having trouble, haven't practiced, have been sick, are feeling discouraged - go to performing songs, playing through lots songs, just adlibbing to lots of music you like – things that are fun and real and within your abilities today. Everybody has times where they just need to consolidate and have fun.
What can I say, it's the 70's and here's the greatest song, "Dancin' in the Moonlight" by King Harvest http://www.youtube.com/watch?v=sR47TZdJg64, the sweetest blend of beauty and rock. It's gotta be that Fender Rhodes.
The sensor that tells you're going flat is the same targeting sensor that will tell you to support and listen and get it right. It's your ear.