As Sherlock lays and goes to sleep, John stays put, feeling the bed move every time Sherlock shifts. He's uneasy, uncomfortable. John swears any minute now, Sherlock might wake up screaming. John remembers the nightmares he had from the war. He shivers slightly.
He turns, reaching out with his good hand and places it on Sherlock's shoulder. "Sherlock." He says. He's doesn't like seeing him suffer. "It's alright. You're alright." He says, giving him a slight push as he shifts to lay back on the bed.
He lets go of Sherlock's shoulder, and lays there, staring at the ceiling. He wants to do more, he wants to hug Sherlock and tell him he's not going anywhere, but he's not sure how the other would respond.