How do I put this... Your persistence is admirable however you might need to read the sticky threads on here and some natural history on this animal. A ball python that is scared to eat and one that does not need to eat are two different things. If a ball does not need to eat, it is not going to eat no matter what you do. During the winter many go off food for months. They are not starving. Once they have enough reserves they will stop eating. I personally like this "feature". I have never heard of a ball eating itself to death. Boas will and will succumb to fatty liver disease if overfed.
How you prepare for feeding depends on what works for you and your snake. Feeding at night is wise. Getting the rat up to the right temp is important. What works for you and your snake works for you and your snake.