I second the request for more detailed info about the setup. The only pic of the setup shows that you're using the analog dial type thermometer, and doesn't show anywhere for the snake to curl up, hide, and feel secure.

As for the feeding problems, it could be stress related due to temps, humidity, lack of a secure hide, etc. It could also be stress related to removing the snake from his enclosure and putting him into a separate "feeder box". This is not necessary, and only causes additional stress and increases the chance of refusals or regurgitation. I would suggest trying to feed in the snake's enclosure, in the late evening when they are naturally more alert and active. You can try the tough love method and only offer frozen thawed prey, however, unfortunately for us as keepers, some snakes will never readily take frozen thawed prey. I understand that the frozen thawed route is often cheaper and more convenient for us as owners and keepers of these animals, but ultimately you have to be willing to do what is best for the snake. And if the snake refuses frozen thawed prey, that may indeed mean feeding live prey.