A Subtle Sadness / A Happy Void (Filling Me Up With Nothing)

Right now I feel Sad 
But it's a subtle sadness 
Which could be easily missed 
'cause there's no crying nor dread 
No feeling blue nor a face flushed red 
As I said - subtle, my wondering why 
I'm feeling §trange, like playing 
"Spot the difference" between Me & 
Me by design, when I'm feeling fine 
Then noticing the only thing missing 
The piece of my portrait that's Happy 
So, this §trange sensation I'm feeling 
A Happy void filling Me up with Nothing