If he isn't eating on his own, then he probably isn't feeling ok with his hide. Although I personally have not seen those hides that you ordered from petco, if all the other members are correct with what they are saying about their size, then they are definitely too big for your little guy and will probably not help him with feeling more secure. I use these hides from reptile basics; they aren't the most aesthetically pleasing but they give your ball python a very good sense of security and they aren't expensive. I have used them for my girl ever since I have gotten her and she has never had a single eating issue. Your little guy looks like he would fit well in the small hide boxes from what I can gather from your images:
http://www.reptilebasics.com/hide-boxes
Also, it might help if you move him into a smaller enclosure. I had my girl in a 6 qt. tub to start. Tubs may not look super pretty but they are inexpensive, come in many sizes, and work great at maintaining humidity. They also give a better sense of security than tanks for your ball python since they usually have a frosted appearance rather than being completely transparent. Hope this helps!