My father died of alcoholism and whatever we said to him or do wouldn't change a thing in his mind. That's a very strong addiction and he didn't stop even when doctors told him he's in terminal phase. I believe the change has to come from inside of you and you must identify where it all started and what was it's trigger and treat that first.

I have nicotine issues but I stopped smoking in favor of e-cigs. Nicotine is not that bad, the cigs are killing you not nicotine itself.

I also find doing sport to change my mentality a lot. You start looking different, you value yourself more when your body changes and you won't want to go back. Give it a try. Good luck to you!