i may be new to this but site but i had a similar problem with a snake i had several years ago, he would refused food for almost six weeks, i took him to the vet after the first few weeks and they couldnt figure it out, and when another two weeks went by i looked for a second opinion and that vet gave me a series of b12 shots after i finished all the shots he was back to normal and back to never refusing a meal. the vet said that they believed it was some kind of infection that was possibly picked up before i purchased him and that it can take months to flare up like it did. the reason the first vet had problems finding this out was come to find out not specialized in herps. i would say if it goes much longer you may want to make an appointment at the vet. ( a good vet )