No Easy Sunday Morning

I lay here (3am) sleepless
My body further sinks into the pitted mattress
I ache
I am in so much pain
but why cry?
The mattress is warm
Perhaps with the blood of my breaking heart
Which weaps
Loudly at first but now simply those silent
shattered sobs
And it beats on
Mocking me
As despite being drained of its meaning
Its soul
It will dutifully beat on
Clinging to my reluctant ribcage
My body feels heavy
knowing it will continue to function
without emotion
Though I'd rather it didnt to be honest
But who am I?