Read some of the thoughts of Feynman, Einstein, and others, they started by guessing, and supposing. Einstein said Imagination is more important then knowledge.
I think you spoke a brutal truth. This poem disturbed me. It is very very good poetry about a horrid event. I can't say any more except you made a picture I didn't want to see.
I googled self-plagiarism and found a decent white paper on it at ithenicate.com. It is new and complex law. My best assessment is change your work a bit if you are going from publication to publication. Hope this helps.