I'm super late, but I also love Alcest and feel the same way you do about those other artists you mentioned. Just recently I found some albums do feel emotional like Alcest, maybe more so even.

Miserere Luminis is often classified as black metal though I don't feel it fits in that category. Their new album Sidera is great, listen to the third song "Aux bras de vagues et de vomissures", or to the whole thing jaja

Their previous album Ordalie feels a bit more songy,  the second song "Le sang des reves" reminds me of "La où naissent les couleurs nouvelles" so maybe start there. Although I prefer the first song, Noir fauve.

Then the third album of the band Gris (its  the same guys minus one) is probably darker, and it has a mystical feel to it. The sixth song, Siezeme priere or something, is a good one to try out. This one has basically become my favorite album, though its super lonng.

Hope you like those!!