Depression can be rather fatal if it's to a certain extent. Addictions can turn lives upside down and become the same as death...I don't know this addiction to pain, but I surely do know how depression works. It's just a really low feeling that attacks you. I think you wrote the poem with skill without error. It's an interesting read and probably will continue to be...Bravo.
I can't imagine anyone wanting to hurt themselves to feel alive, you would think that everytime they wanted to do that to themselves that they would stop and listen to thier heartbeats in a very quiet place and take in very deep and short breaths and say hey I'm alive what else can I do besides what I am doing. I lost my little sister 3 years ago, she is no longer doing drugs, and she is at peace, but I know for a fact that that is not how she wanted to stop! I wish there were one big cure for all addictions.
While poetry is meant to express yourself through, this poem hurt. Because of the reality, or maybe because no one at 18 or 19 should have so much pain to cause this. Though I've been some very dark addictive places, you make me ache for you. I join in the previous comment, peace and joy. I hope you find your way back soon. Until then, you're in my prayers and good wishes.