Your temperatures could be a little higher, I think keeping him closer to 85f(29c?) Is ideal. Wheat worms/mealworms aren't the best feeders for these guys as their shells are hard to digest and they're not the most nutritious. Dubia roaches or night crawlers are ideal, even gutloaded crickets would be better if you can't find those. And like the person above said, amphibians are extremely sensitive to the chemicals in tap water, so you'll want to use a water conditioner like for aquariums to neutralize them. Make sure you do this for the water in his dish and the water you use to moisten the soil. Hope he feels better soon!