I think your right he does need to have a plan. I right a weekly day to day plan on with things to do each day and tick it off. Meditation is working wonders for me and their are lots of apps.
Believe me having a kid will not make him stop. I have had 2 since my 1st coke, and I said on both occasions I’d quit for them. So that won’t work. He has to hit his rock bottom I guess. That’s what most people say. Don’t go getting pregnant thinking it will stop him quitting. Trust me it will not lol