You can try adding a nice cave to make him feel safe.
Try feeding nightly. Drop a cricket in and let it run around for a bit. If he doesn't eat it within an hour or so, you can take it out.
As everyone has mentioned, get that substrate moistened up so he doesn't dehydrate.
Be sure your pedi soaks are 1 part unflavored clear Pedialyte to 10 parts dechlorinated or spring water, as mentioned above. Soak him right in his own water bowl so he's not too stressed by handling. After his 15 minute soak, rinse out the bowl and replace with dechlorinated water.
Pick up some Repcal calcium with vitamin D3 for when he eats. Dust his food every other day with calcium/D3 and one day a week with the Repashy vitamin.
Let him destress a couple more days. If he doesn't start eating on his own we can teach you how to gently manually (force) feed him. Feed at night with the lights out or very dim.
He's quite the cutie.