I would get the humidity lower to around like 50 to 60 and get a uvb bar light and a ceramic heat bulb that emits no light, also put the cage next a window so he has more stimulation. that is why he is sleeping and not doing anything all the time which is making him weak cause he is not using...
Also if you have cats or any other animal make sure to put a towel or something over it so she doesnt get spooked and gives up on the hole she is digging and yes it look very dry
Well first things first, i would recommend getting a bigger cage so you want have to upgrade later when he or she gets bigger. I just build a 24"x 24"x 72" cage so I could get another chameleon and my female veiled was not happy with the cage that i had which is the exact same one you are...