My leopard gecko has a problem?

Yesterday i got a juvenile hypo tangerine leopard gecko.Im not sure what gender he is.I fed him two dead mealworms covered with calcium d3 supplement. The mealworms were about the size of his head. Another thing is that i have a heat pad under his tank that heats the air to about 78 degrees.Today he was in his moist hide but under the paper towel. I panicked and took the paper towel from th hide to see him. right now he is just setting in the moist hide with his eyes half closed and one arm that is straight out on the ground. Yesterday night he was very active though. I dont think he has slept since i got him. can someone tell me what wrong with him and if there is something wrong with him.