I have no sage words of advice on how to talk to your son.
I've talked to my 33-year-old addicted daughter more times than I care to remember, to no avail.
On top of that, I am a long-term recovering alcoholic/addict (21 years) and she has paid no heed to what hell I went through in my own addictions.
If ever she seeks help, I'm the last
person able to help her. She needs other addicts in recovery (excluding me) who can give her guidance. I'm too close to the problem.
I am so sorry for the heartache that your son's addiction continues to bring you. As someone has said here on SR, being the mom of an addict isn't for weenies. It's a tough job.
Sending you hugs of support!