Check out your supermarket or Whole Foods, or farmers market, they maybe selling opuntia cactus pads and dandelion greens. I don't know about the sulcata, but have some experience in getting a sick baby tort to eat and feeding it for many months until things get turned around and he started thriving and growing/putting on weight. Now he is not-so-little anymore heavy "moving rock" and eating machine. Your little sully does look pretty emaciated. How much food do you offer? How often? I'd treat him as "sick or recovering tort" and as such soak daily, feed twice a day or more if needed. The amt I offered to mine for 1 feeding was at least a size of his carapace, 2-3 times a day. And we are not talking about "fluffy salad" that if you squish it down becomes thin pancake. I chop up my food, everything: the greens, finely dice up cactus, soak and mash up Mazuri and mix it all up. The consistency of it is kinda like deli potatoe salad only much more finely chopped. Again my area of "expertise in tort nutrition" is in RFs who are omnivorous, but the principles are this same: pack good calories, vitamins, minerals (esp. calcium) in form that's easy for them to take in. Grazing takes work. Sometimes those sickly babies just don't have enough stamina to graze long enough to meet their nutritional needs this is the example of my torties' breakfast then i topped it with fresh edible flowers. This pile is about 1.5 cup of dense food. If they clean it up in like 10-20 min, I add more. If they don't I feed them again in the afternoon. Feed enough that there is ALWAYS some left over food. Bring him out and put in front of his food. If he nibbles and goes back to his hide, get him back out. You may need to repeat it many times before he catches on. Also keep him well hydrated, and warm, and UVB and with all that... I'm keeping my fingers crossed for you