That's because old behaviors and habits are hard to break. Don't stay long in self-pity, get back into the family and act like the parent you don't feel. The truth is that feelings come and go, behaviors stay. Children are victims of negative habits as well. When this happens, it is called a negative family script.
Family members fall into old styles of interaction.
Children will continue to treat the parent in this old way. Parents can do a 180, meaning they can reverse directions, and do the opposite of what isn't working. Instead of yelling, whisper. Instead of talking in the morning, try the evening. Instead of lecturing, tell a joke.