I wrote 2 versions of this the other is entitled The Darkness and it's in Dark Poems if you wanna check it out.
My darkness
I used to be shrouded in darkness
Dark thoughts would cascade and compress
Then you came oh one so bright
And bathed me in your radiant light
But light in time dims and weakens
All the while darkness grows and strengthens
It's getting harder for me to see
If it takes hold again what will become of me
The light is now just a dim glow
But I resolve myself not to let it show
Laugh and fake a smile for you
Wonder how you'd react if only you knew
This blackness almost has me now
I don't know when and I don't know how
But the thoughts will return
And blood must run and flesh must burn
It is stronger this time, so strong
It seeks to assimilate me and it won't be long
I can feel it now I've got nothing left to give
And I'm slowly losing my will to live
I take a blade to my arm and I cut deep
The blood slowly appears and begins to seep
I lay down on the ground and I wait
Cold and tired, resigned to my fate
And as the blood runs the light disappears
And with it all my hopes dreams and fears
I close my eyes as the last of my blood drains
The light is gone only darkness remains
