HELPPPP. my beardie "Rango Forrest Homes" seems very ill, hes not himself and I just know something is terribly wrong

So I moved December. Once I got here I realized my boy needs a bigger tank. Well he was glass surfing like crazy. So doing my research i found his tank was too small. I went from a 40 to 90 gallon now. Ever sine the change hes been a different boy. He hides, sleeps nonstop, and the little bit of time i see his eyes open and I go near him he literally closes his eyes right away. almost like he is mad at me. I changed from crickets to roaches at same time of moving bc nowhere to store them here, I had a cricket tank at my house. His poops seemed normal but little by little he stopped eating at all. ANd the poops are pretty non existant as well. he wont touch the veggie, bugs...Nothing. I finally got him to eat two roaches last week and maybe a bite of collard greens. Im really worried he is very ill. This is not like him. He was a great eater, very social, loved being held and one more thing. His tail is dark brown about last 3". I brouhgt him to the vet and they said to keep doing what im doing which is using the spray I purchased for tail rot, Ive also done betodine /water soaks, and electrolyte baths. Idk what else to do. his eyes look good his body looks good. but hes just different. ANyone have any clue, besides stress, that could be causing this? Im sure hes stressed with the move but its been months now. Please help!!!! Also Im having hard time getting this larger space heated to 100 degrees but i have heat pads and added another 150 watt basking bulb. SOMEONE HELP ME Im Sick to my stomach. I love him so much!!!!