Palpatine is dead. And his father is alive. Some might contest the actual state of his health, and his validity as a father figure, but to Luke, he has his father. Not back, no, because he'd never been anything but a fantasy to begin with.

For the first time.

He thinks it will be hard for him to fall asleep, but it is a matter of minutes from his head hitting the ground to fatigue overcoming him. This does not mean the Force is done with him, however...