light + aquarium = dehydration city. If you're going to go with that kind of setup, you HAVE to use some plexiglass or something of that nature to keep humidity in. A dehydrated reptile will not be interested in eating, and will not be able to digest a meal properly even if it does.

Also, you really need to provide a temperature gradient. It sounds as if you have the entire tank at 92 during the day, which is much too warm. Only one end of the tank should be at that temperature, with it being around 80 at the other end. If you're unable to provide a proper gradient in the meantime, I would keep the entire tank at 80. Actually, for a hatchling, it may sometimes be a good idea to keep them at a steady 80 all the time since in the wild, they are born during the wet season which is a little cooler than usual. Either way, make sure it has access to a temperature of 80 at all times.