the sound in my head when I cannot sleep a few days ago is the first bar in this sheet music:
(I figured out later that the sheet music can be simplified if I use the 12-4 time signature, but it will take time for me to edit the sheet music. Here’s the MuseScore file for you to edit if you want it to see it in 12-4.)
Update:
That is not really the sound of “I can’t sleep” 
. I was just listening to Chopin Nocturne Op. 9 No. 1 in B-flat Minor while trying to get to sleep when I cannot sleep, then that sound popped in my mind.
