What I can tell you is 70 degrees is way too cold for these frogs, so he may have been trying to aevistate and would explain his lack of appetite, which they shouldn't be allowed to do when very young. Bump up the temps to 82 degrees during the day, and 78 at night. That should at least boost his appetite. For more info, until someone more experienced then me responds, read this if you haven't:
Frog Forum - Pacman and Horned Frogs - Ceratophrys - Care and Breeding
Also UV light is not necessary, especially if your frog is an albino. It hurts their eyes/skin/may cause blindness in the long run. If you need a heat source of some sort, turn to infrared bulbs instead. No more than 50 watts. And if you need a light to establish a 12-hour daylight cycle, just use a 15 watt household bulb.
And you say your substrate is mixed with frog moss? Is it the "pillow moss" or the "forest moss?" The kind compressed into a brick. If the brick I'd change it to pure coconut fiber. Forest moss is a huge impaction risk.