I think that the translation word by word is correct, but it seems that the requester wanted something more "poetic" so what about : Why does your heart needs healing" or " why does your heart needs recovering". Don't know, but perhaps the requester would prefer this.
I think that your suggest is a good one Lene, THANK YOU! (Much better than "repair".) But since Audhild suggested "mending" in a pm, I'll edit to her own suggest.