Give the frog some more time to settle. Because White's tree frogs are captive bred there's probably not going to be parasites or any other disease, not saying it's not possible but less likely. If the frog was going to starve it won't still starve even if you brought it to the vet because it takes time for fecals to come back and to actually treat the frog. However I think I read that frogs can adapt their metabolism to suit the availability of prey and temps. The most important thing is to make sure conditions are right. Also feed at night, remember the frog is nocturnal