Nat mur at 30c (x) hardly exhausts the potential of one of the major anti psoric remedies.
I would certainly go up the potencies before abandoning it.

Constitutional Remedies certainly exist - take a look at Dr Clarcke´s book on Constitutional Remedies of Von Grauvogl.

At the same time both Hahnemann (zig-zag) and Compton Burnett (ladder of remedies ) confirm that often the road to cure is a trifle tortuous .