One that I have had for three years is now suddenly
wilted, and the leaves and stems are very soft and limp
to the touch.

I've seemed to have that problem from two different sources.
Either not enough water....or too much. Either way it is,
the stems that are very soft don't recover or at least
they haven't for me. I've had it happen so that there
are *no* leaves/stems left but if I've babied it enough,
it will start growing again, as long as the crown ??
correct terminology?? hasn't rotted also.

Tracey