Hey Ryan,
TJ's point is well taken. If you have a decent heat gradient already at the hot end, cool the rest of the cage down a bit.
Also, take no offense to this, but if you are using that big bowl shaped hidebox for a tiny alterna, that could be improved. Alterna love to be tightly hidden under stuff (cracks in rocks is where they hunt, but they live in tighter underground areas that are cooler, humid and dark. That is why I suggest aspen shavings because they can tunnel, make their own hiding spots and it really allows for temperature gradation to be determined by the snake.
Additionally, I don't know how often you handle him or if his cage is in a high activity part of your house, but now would be a time to keep him quiet and leave him alone. Sorry if this obvious to you...
If he is in good weight, you should be OK for bit without him eating, and you may make it through a winter cooling period to try in the early spring late winter.
A water bowl in a cage with an open top does little to add humidity. I don't know how you cover your cage. However, alterna love damp moss in a plastic container. They may not use it all of the time, but they will spend several days a month in one of these set-ups, and not always associated with their shed cycles.
Hope he turns around for you and good luck.