Hi Vernet - Younger, smaller tip cuttings will root much more easily than older, longer, thicker stem cuttings. For the latter, it is best to air-layer them rather than taking a standard cutting.
Your cutting is very large with many leaves to support while it is slowly trying to develop roots. It is unable to do that and that is why the stem has a shriveled appearance and the leaves are starting to wilt. If you were to pull it out of the soil, I'm sure you will not see any roots and the end in the soil will be soft and mushy. It is very unlikely to make it, I'm afraid.
You might be able to salvage the top 4 or 5 inches as a cutting rooted in water, although even that does not look promising at this point. Sorry