Have you tried scenting it with tuna water? I had some hognose snakes a few years ago that had the same problem. What I did, was go to the store, buy a can of tuna fish in water not in oil, come home drain the water into a ziplock bag. Then I took the bag and froze it. When it was time to feed, I would get the mouth a little bit warmer than usual and then rub its head on the block of tuna water ice. Those hognose snakes love them that way. I know what its like when they don't feed, it just creates an anxiety attack.