I think that's a pretty long time. Mine went 3 weeks and 2 days once but really seemed to be weakening. That was a few months ago and she's going strong now but I really had to nurse her back to health. I would go out *tomorrow* and get some waxworms (they're almost irresistable). Cut a small piece off the waxworm (1/8 to 3/16 of an inch) and hold the cut end to the lizards mouth with a tweezer. I had to really keep at this until she took a small piece.
The thing is, why isn't it eating? What's your setup like? I think my setup was too small and I think it caused stress. She's in a 20gal tank now and doing well. Does yours drink? BTW, I'm not sure that calcium gravel is the best thing for them but I'll let some experts chime in on that.
Andy