"I can sometimes find them if I focus, but I don't feel them here." It's distressing because of the situation they were in before, but the Winchesters have fought and lived and done a million things that no one thought was possible. He needs to have faith that they'll be okay until he can get back to them. Until then, he can try to do what they would here. Survive, do his best, and look out for other people.

He brightens at the offer and smiles, nodding. "I would like that, thank you. I'm not scared of the dark, to be clear, but I would appreciate some company." It would be laughable for a hunter to be scared of the dark, at least more so than they are simply apprehensive for what lives in it. It's more that Jack is just lonely. After all that time in the Empty and then on his journey with Billie to self-destruction, he is tired of being isolated.

Jack shuts the door to his room and puts his hand on it, placing an invisible mark on it so that if anyone does try to break in, he'll be alerted. And they'll be sorry for it. Not that he has anything important in there yet, but he does have some money. "I've never lived in a city before. My home is in a small town in Kansas." That might explain some of the sheltered aspect, with or without all the rest. He's always seen the bunker as his home.