My head

It's a ringing in my ear.
It's a low hum I hear constantly.
It's the sound the old air conditioner makes when it comes on, and in the house that is my head the AC is always on.
It seems cold in here.
Maybe you can find a jacket to wear, to warm you up, but nothing does the trick long-term.
I can be with my best friend having a good time but I still feel it, the infinite sadness that lives within me.