I love your descriptions of the Black Forest! I actually grew up there and it reminded a lot of home. I looked through my reading list and didnt really find any fantasy that matched exactly. I read a thriller "the sanatorium" by Sarah Pearse which was quite good but i think it was set in the alps. "Yesteryear" is a novel set on a farm in the middle of nowwhere surrounded by trees and it definitely has some sort of gloomy vibe, its some sort of dystopian novel? Im not sure. And i also loved (!!!) "The serviceberry", which was part of the winter readalong. Its a short non-fiction book on gift communities but it refers a lot to the bond native american and their tradition had to nature. Made me appreciate my forest even more! And i read online that the Shepherd King books by Rachel Gillig have same sort of dark, gloomy forest vibe.

Ill definitely hang around this post peeking at the recs :))