Ok, so first of all, he needs two real hides. Some fake plants as cover are not enough. Usually works best if the hot and cool hides are exactly the same. This keeps them from choosing a hide they like over temperature. Second, your temp on the cool side is boarder line dangerously low - 75 is the ambient it sounds like. Anything below 75 and they can start having issues with digestion and respiratory infections.
The gradient should be 78-80*F cool and 88-90*F hot in the hides with an ambient temp 80-82*F.
Putting damp towels in the tank can lead to the bedding molding, and the towel itself. It would be better to put damp sphagnum moss on / in shallow plastic bowls that keep the moisture out of the substrate. Also, if it has been a month he may not actually be in shed - what morph is he? Some are washed out or dull like ghosts. Also if he is not eating he will not shed.
He is probably not eating because your husbandry is off and he is either too cold, too exposed, or a combination of both. Cover three sides of the tank with dark paper (on the outside), get correct hides, cover 2/3 or slightly more of the lid with foil or plexiglass, and get some good substrate for humidity or sphagnum moss.
You can also give him a third hide that is a moist hide - this is a hide like a rock den, terra cotta flower pot, or something else that you put damp (not dripping) sphagnum moss into. I keep mine on the warm side so that moss isn't chilly.