34 grams isn't necessarily a bad weight for an adult male. males tend to be smaller and leaner than females. do you know if he ate cgd before you got him? if he is eating crickets that is a good sign. he may have slowed down a little if it is cooler now than where he was before. cooler temps cause slower metabolism and therefore they will eat less.

do you have someone to take care of him while you are away? make sure he is staying hydrated and try mixing some baby food in with the cgd if you haven't already to get him started on it.