This interaction between the two of you, about his recovery program,
seems to be fueling your codependency. The reenactment thing blows my mind and I mean no snark here when I say your pride ( implies you feel you contributed to or otherwise caused the outcome) that he completed the first step is akin to a mom clapping when her son, at long last, makes his first pee-pee in a pot, instead of a diaper.
Your emotional stability seems tied to his outcome which is unhealthy.
As for feeling responsibile ( the source of guilt) for engaging in an interaction between father and son that became the excuse for him to use is silly. Are you going to spend the rest of your life making certain he is never in a situation that might cause him to be angry, anxious or uncomfortable?
If he decides to crash and burn again, you have set yourself up for a spiral right along side him.
Surrendering/accepting that we have no power over other people and their choices is the foundation for recovery from codependency.