Now that I saw a better picture, it does appear that it isn't happy.
There could be any number of reasons: Flow, lighting, lack of H2O changes, maybe even suffering from toxicity from your softie...In a small tank like that, a slight change can make big problems.
Again, I'm also concerned that you've had it for 1 year and it has stayed 1 single head. Maybe it has just been barely hanging on that entire time?
Wish I could offer more help...best of luck!