How to make my cat comfy (just returned from the hospital)?

He's 13 yrs old and just got back from the hospital after being attacked by two German Shepperd's. Are neighbor thought he was dead and he was stiff as a board but now he's fine but he is sleeping a lot and he's not eating very much? He used to be very active and now he doesn't want to be around anyone? I think it's because he feels bad about being shaved (IDK Why they had to completely shave him i guess cause he was so bit up and it's Florida in the summer so it's not like he needs it). SO how could I make him comfy?