Why isnt my corn snake eating?

she is about 6 years old now and has been eating every 3-4 weeks for about a year or so now (used to be ever 1-2 weeks when she was smaller). Now all of a sudden she wont eat and hasnt in 2 months or more and has shed twice in that time and is burrowing a lot lately too. She laid infertile eggs quite a while back so I dont know if maybe shes going to do that again...thoughts? Please help, my husbamd wont let me bring her to the vet cuz its too expensive.