As a native German speaker, I can at least say that knowing both German and English doesn't really help in understanding the text. Not even the most "dumbed down" version - ok, he's apparently saying something about his wife, but no idea what exactly. And when I read "shyne (Modern English "sheen" but German cognate is closer)", I was even more confused. "Sheen" is the property of an object that is shiny, which in German would be "Schein", but because it is applied to a woman, I assume that the "cognate" he refers to is "schön" (beautiful)?
Another Modern English cognate even closer to shyne than "sheen" is "shine" (and obviously the German "schein"). The words for "beautiful", "fair", "bright", "shining", "well-reputed", "righteous" have a long history of being related:
https://en.wiktionary.org/wiki/schinen#Middle_English (to shine, to appear)
https://en.wiktionary.org/wiki/skyr#Middle_English (clear-coloured, pale, light, luminous, radiant)
https://en.wiktionary.org/wiki/sciene#Old_English (beautiful, fair, brilliant, shining)
https://en.wiktionary.org/wiki/Reconstruction:Proto-Germanic... *skīnaną (to shine, to appear)
https://en.wiktionary.org/wiki/Reconstruction:Proto-Germanic... *skīriz (pure, clear, sheer)
https://en.wiktionary.org/wiki/Reconstruction:Proto-Germanic... *skauniz (beautiful, shining)
and ultimately the PIE
https://en.wiktionary.org/wiki/Reconstruction:Proto-Indo-Eur... *(s)ḱeh₁y- (to shine)
There are cognates absolutely everywhere in modern Germanic languages:
https://en.wiktionary.org/wiki/sk%C3%ADr#Icelandic skír (bright, clear, pure)
https://en.wiktionary.org/wiki/skir#Swedish (sheer, delicate, shining)
And even in Slavic languages:
https://en.wiktionary.org/wiki/Reconstruction:Proto-Slavic/s... *sijati (to shine, to illuminate)
Skauniz was even borrowed to Proto-Finnic and highly conserved in modern Finnish, Estonian, Ingrian, etc. which all have kaunis meaning "beautiful"!
https://en.wiktionary.org/wiki/Reconstruction:Proto-Finnic/k... *kaunis
Words to do with light are so subtle between German and English. Like Kraftwerk tells me neon lights are "schimmerndes" in German, which I will take their word on, but they also say they are "shimmering" in English which is definitely not true.
scyn/schön/sheen are a different root from schein/shine, for what its worth.
Also I realise now "forlet" is very archaic in modern english whereas "verlassen" is very common in modern german, which would have helped.