Congrats on your new BP. I would make a few changes to your setup. For starters I would replace the heat bulb with an under tank heater. Heat lamps tend to suck humidity out of the enclosure. You also want to make sure your heat source and temps are controlled by a thermostat. I think your temps are a bit cool which could cause the snake not to eat. You want a hot spot of about 90F with ambient temps around 75-80F. It's easy to create the hot spot with a UTH and you can supplement the ambient temps with an IR heat bulb or CHE on a dimmer or you could use a radiant heat panel as your sole heat source. You'll also want snug hides on the warm and cool sides of the enclosure. I would make sure your temps and humidity are dialed in before any more attempted feedings. Give the snake another week to acclimate to it's new environment once your husbandry is up to par. Make sure your prey items are completely thawed and warmed up to about 100F before offering them to the snake. Feeding snakes inside their enclosures does not make them more defensive. That is a myth. I believe feeding them in separate bins causes the snake more stress and could lead to regurgitation when moving the snake back to it's enclosure. All of my snakes are fed inside their enclosures. I'd also suggest getting your BP on rats ASAP. Eventually one mouse won't be enough and it's easier and less expensive to feed one rat as opposed to multiple mice. Lastly, since they prefer tight dark spaces, I would cover 3 sides of the enclosure to give the snake more of a sense of security.