Psalms 56:8

This is my very first poem on her and so I know it's not very good but seriously everyone please be brutally honest and I would appreciate all the help I can get! Thanks and let me know what you think.

sitting alone in her room
behind closed doors
music so loud
She can't hear her own tears

her head pounding and
pulse racing
she tries to ignore the pain in her chest
her throat slowly closing
numbness slowly creeping over her

gasping for air between each breath
Finally she gives up when knowing
it can't get any worse
She whispers to herself
"no one knows, no one cares"
the words sinking into her soul
leaving their mark

All she wants is to escape
then she remembers Psalms 56:8
slowly her body unumbs itself
starting with her heart

You've got a nice pace in here, and the emotion is really raw. Good job with that.
What I think you could improve is the originality. Position the subject somewhere else, or maybe don't mention exactly where she is right from the beginning. Your first line doesn't really captivate the reader. I for one feel like I've read about girls sitting alone in their room many times before.
Something else you might add...why is she there? Maybe you could develop a backdrop; that would definitely make the poem more interesting.
The last stanza is nice, but it seems a bit cliched.
Anyway, I liked the way you conveyed the emotions in detail. I think this work would benefit a lot more if you tried to make it more your own; add maybe some personal observations, or little things that makes the situation come to life.