I'm not quite sure what kind of comments you want for this piece, so I shall just speak my thoughts!
You seem to have created an interesting paradox here. You compare yourself to nothingness, to dirt, to a shell, which I understood meant you are empty, yet you love; you fear yet you are not afraid; you feel pain, you feel sorrow, yet you are protected by love. In some poems, a paradox is a powerful way of making something stand out beautifully, but it is a bit confusing here, I think.
Still, it is well written. I especially liked the end: "But this I choose, But this I am." It sounds pleasant to the ear, and it closed the poem well.