both my parents are useless drug addicst and have been since i was little. dad is in prison for the rest of his life for drugs. and i stop by my mom's house 2-3 times a week to make sure shes still alive. i literally cant remember the last time i saw her not completely strung out. for most of my life growing up, this kinda stuff was all i knew.
they may have good intentions, but they will lie, cheat, and steal to get what they "need." if he's still having withdrawals, like said above, hes either still using or he needs to be an in-patient somewhere. it really says a lot about you to want to help him out. be there for encouragement and someone he can talk to. but you are not going to be able to help get him clean. he needs professionals, and even they'll have their work cut out for him. if hes in your home, hide anything valuable. and addict will steal from their mother when they get desparate. they can be so close to being sober and all it takes is one tiny slip and theyre right back where they were.
its great that you want to help, but use caution because anyone around is at risk. its sad, but its not worth putting yourself and your family in a situation like that. maybe im a little harsh on this part from it affecting my life from day one even tho ive never touched any of it. but theres really no excuse for it. ive had a rough life growing up poor white trash and never fell into it. and theres people that have had it a whole lot worse and never got involved in drugs.
bottom line is they made a choice and its up to them to get clean. by all means, offer encouragement and support. but be very careful not to get too deep with it. an addict going thru withdrawals that decides they absolutely need a fix is one of the scariest things you'll see