How To Help....

My husband has been addicted to pain pills for the past few months, Im not sure what they are called, for he has just now come out with everything about it. His mother is a nurse and she has alot of perscription drugs around the house (we live with her) so it's easy for him to get them (Vicodens, Percocets, Ultram;s, muscle relaxers, ect,). I know it's not any of those. But to get to the point of this, he stopped taking them about 4 days ago and is going through withdrawal from it, he's very depressed, he can't sleep, he feels very lonely and he's extremly emotional. What can I do to help him besides try to be there for him and keep his mind off it? I have no idea what to do to help and I feel so awful. Everytime I look into his eyes I can see his pain and I want to help. And does anyone know how long withdrawal from pain killers usually lasts? He said he took about 4 or 5 a day if that helps. Please, any advice would be be great.
I would start with finding out exactly what he was taking so you know what you're dealing with.