Longing for a home that no longer exists or never was

I looked again at our blazing spiral [the milky way] and was homesick in a way I hadn’t been since I was six.
«Have Space Suit will Travel» by Robert A. Heinlein

I love the word «sonder» (realizing «that each random passerby is living a life as vivid and complex as your own»), but I guess «hiraeth» is right up there with words like «sonder» that convey … a lot of meaning. Looking at a definition:

Hiraeth (pronounced [hiraɪ̯θ]) is a Welsh concept of longing for home, which can be loosely translated as ‘nostalgia’, or, more commonly, ‘homesickness’. Many Welsh people claim ‘hiraeth’ is a word which cannot be translated, meaning more than solely “missing something” or “missing home.” To some, it implies the meaning of missing a time, an era, or a person. It is associated with the bittersweet memory of missing something or someone, while being grateful of that/their existence.
Wikipedia via https://www.definitions.net/definition/hiraeth

or

hiraeth (noun)
a homesickness for a home that you cannot return to, or that never was
Submitted by landonallmon46 on October 26, 2021 on https://www.definitions.net/definition/hiraeth

And yeah, that is a feeling. Especially the last definition.

Hmm, but if that home at least existed, that is still something. To quote Mrs Hughes in «Downton Abbey»:

«If you’re feeling homesick, there’s no shame in it.»
«No.»
«It means you come from a happy home. There’s plenty of people here would envy that.»
Downton Abbey

Hmmm, two years ago to the day that my father died. Hmmm.

[If I could, I’d add a sad-melancholy-expression-emoji here, but none fit.]