The Shelah on Mourning the Temple and Inner Holiness

The two passages from the Shelah's Bayit Acharon that are available — Shenei Luchot HaBerit, Toldot Adam, Bayit Acharon, Sha'ar HaOtiyot, Kedushah and Shenei Luchot HaBerit, Toldot Adam, Bayit Acharon — teach that a person who perfects himself through his deeds, Torah, and the purity of his limbs thereby completes and rectifies all his limbs in correspondence to the structure of the great cosmic Adam, each limb perfected through the mitzvot particular to it.

That teaching is a doctrine of correspondence between human self-perfection and a supernal archetype, not a treatment of Temple mourning as a path to rebuilding inner holiness — and the question's specific theme does not appear in those passages from Shenei Luchot HaBerit, Toldot Adam, Bayit Acharon, Sha'ar HaOtiyot, Kedushah.

The one source on the sheet that does address Temple mourning is Kaf HaChayim on Shulchan Arukh, Orach Chayim 560:1, which notes that after the Temple's destruction the Sages enacted that every occasion of joy should include a remembrance of the Destruction, anchoring that enactment in the verse 'If I forget you, Jerusalem' and tracing it to the Gemara in Bava Batra — but this is a discussion of rabbinic enactment, not of inner spiritual rebuilding.