If your Rhino is 7 weeks old than it should have been eating greens and other veggies six weeks ago. How long have you been feeding him baby food because that is not a healthy balanced diet. If you ever do get him eating on his own he's certainly not going to accept greens well if you've force fed him tasty baby food everyday. If you must force feed him than blend up a properly balanced diet with fresh ingredients, supplements and put it in a large syringe. What was he feeding on before you got him? Sometimes springmix is good to get them started but that's a few days after they've hatched. What's your ambient and basking temp? Any UVB lighting? Iv'e had my fair share of reptiles over the years and 95% of them I raised from hatchlings. I learn new stuff all the time, constantly humbled and remain hungry to continue learning.