Hi Elliemay. Welcome to NGA!
I don't know anything about your particular plant, or what the original problem might have been. Disease sounds plausible.
When you re-potted, was it root bound, or maybe had very few, thin, sickly-looking roots suggesting root rot? Anything like grubs? If a potting mix retains too much water, it doesn't help enough to under-water it, the root hairs still go through periods of not-enough-oxygen, alternating with not-enough-water.
But I seem to see baby leaves just starting to emerge, towards thee bottom of the first photo. If so, it's far from dead.
Hopefully they will at least grow out enough for you to take new softwood cuttings.
I don't know whether the top few inches of that semi-woody stem would make a good cutting. I'm guessing not, becuase it looks pretty unhappy and has no new leaves yet.
