My first Ball Python that I owned was a hatchling my parents bought me as a child. It died 5 days after we brought it home. The pet store that we purchased it from did a necropsy and determined that the aorta had ruptured and it was just a defect that the snake was born with. The moral of the story is that things completely out of your control can and will happen. It sounds to me like you're doing a great job.