How awful. You might consider Families Anonymous or Alanon. Or contact narcotics Anonymous to see what groups they might have for you as a parent.
Personally, I like the idea for this push for rehab. BUT …I’m not sure repeatedly. It seems a desire for change must come from the person.
And you must protect yourself and work on your own good health and happiness.
There is a Substance Abuse Forum here too.
I’m sure others with more experience in this topic will come forward.