kylo-ren-is-my-trash-boy asked: Is there a word for the feeling you get when you want to return to a place you can no longer return to, like missing an old house that's been sold or a time when you were young?

word-stuck:

Hiraeth is a deep, wistful, nostalgic sense of longing for home — a home that is no longer or perhaps never was. 

Pronounced [hɨraɪ̯θ], this Welsh word is defined as a yearning and wistful grief for people and things long gone, a homesickness tinged with grief or sadness over the lost or departed. 

It is a mix of longing, yearning, nostalgia, wistfulness, or an earnest desire.

Hiraeth bears considerable similarities with the Portuguese concept of saudade, Brazilian Portuguese banzo, Galician morriña, Romanian dor, and Ethiopian tizita.