Well if it helps, you're not alone, this must be the most asked question in the last 2 months by a long chalk. If there's no sign of growth or recovery by mid April, you can try cutting the central trunk down by half in hopes that forces growth either from the base, or some way up the stem. If you cut it and its soggy, its a goner, though it might shoot from the base, below the mainstem even then. If no sign of anything by end of May, its a goner, I'd say.