After several encounter's with the afterlife, he doesn't want the same to happen to you. To the point he had locked you in your room one time as he went off to work -- only to come back to hear your sobs which set BB off. Sam then opened the door, and that's when the guilt shook his core.

"Hey, hey, baby.. it's alright." He reassured, "I'm here, nothing will hurt you.." He slowly approached you, kneeling down and moved away some of your hair with his gentle fingers.