The Sandman is my new obsession and it haunts my daydreams.

I wonder if Sandman inspired Enter Sandman by Metallica. No results of connection between the two on regular search appeared.

https://wiki2.org/en/Dream_(comics)#The_Dreaming

Morpheus lives in a castle at the heart of his realm, "the Dreaming". Both the castle and the rest of his realm are mutable and change often, often at Morpheus' will, although his resistance to change (and difficulty changing) is a theme throughout the series. Morpheus maintains both the castle and the realm, as with all aspects of his appearance, in a half-accommodating, half-terrifying state, simultaneously acknowledging both the courtesy due to others and the attention due him as the realm's master, and indeed the pleasantness and terror of dreams themselves.