Do you know where the frog came from if it is wild or if it is captive bred? Most in the pet trade, I hear, come from South Florida where humidity is rarely even 60% so I can't agree on the low humidity, but 60% with a good amount of air circulation is probably the best way to go as far as that.
Anyway, what are the temps in the cage and are you providing a heat gradient? Are you using a heat lamp as a heat source?
Your frog will not ever get lonely, so don't worry about that, but I'd take the recommendations given and ditch the substrate for ground coconut husk (Bed-A-Beast, Eco-Earth, Forest Bed, etc.). I'd also try a fecal and, as mentioned, make sure the frog has green things to hide in. Let us know what you do and if the frog gets any better. It really could just be stressed from things, but who knows.
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Got hips like Cinderella / Must be having a good shame / Talking sweet about nothing / Cookie I think you're Tame 