i know that smashing everything in your room and punching a wall isnt exactly self soothing, but it also kinda is, ya know? eddie taking the distress out on the wall, and destroying his room and then sitting with his back to the door, on the floor in almost a corner. he's putting himself somewhere safe – subconsciously – and having the bat there to again sooth. He's protecting himself with the bat in front of him, which would be more self soothing. and then once hes out of the bedroom, he crosses his arms and pushes himself into a corner yet again. people cross their arms to protect themselves from emotions, and to hold themselves. hes literally giving himself a hug. 

and hes being doing it so much. theres so many scenes of 5b of eddie with one or both arms over his chest. in the kitchen with chris he said there hugging himself until chris came for a hug.