Explain depression,please...

**how i feel when i am depressed**

Its like going down a tunnel
With no lights to see
No one to keep me company
Just myself and me

Running non stop
Trying to get to the end
But always tripping
On my feet, I cant depend

The walls close in
And I cant breathe
I hate living this depression
I hate this damn disease

I stop to take a breath
But the silence is to hard to bare
So scared to an extent
I drop to my knees in prayer

Dear God, father savor
Save me from this path I have took
Do you still see me?
Open your eyes and look!

I shiver and freeze
Shake because I'm cold
No one to keep me warm
No one to hold

Its like going down a tunnel
With no lights to see
No one to keep me company
Just myself and me