Hello there,
The Center for Motivation and Change has some incredible resources for partners and family of a person with a substance use disorder.
They also train folks across the country in a group model, called CRAFT, that is for the family and friends of people with addiction. The model emphasizes self-care for the family and friends while also teaching them that they don't have to withhold love to help their loved one. Withholding love was the primary tool used for a long time and it's not evidenced-based at all. These groups essentially teach motivational interviewing skills and around 60% of the people with the substance use disorder seek treatment after their family and friends attend the groups (and the people with the SUD didn't attend the groups!). Really powerful and really worth checking out and spreading.