I love the part of this article, where they talk about the "stress dump." The author says children will call out of the blue to unload on their parents about college problems. "Kids will often call their parents and do what we call the ‘stress dump’ to unload their frustrations." It's uncomfortable to be dumped on, sure, but knowing it's normal and expected can help.
If you are facing the Empty Nest - hang in there! It WILL get better!
If you are Empty Nesters already, what has it been like so far? Are you adjusting?