My sister had been a functioning alcoholic for as long as I remember. I didnt do anything about it. Rarely I made a gentle comment, mostly I ignored it. She retired about a year ago, suffered the loss of a close friend and beloved pet. She became no longer functional. I finally got the courage do do something. My husband had serious health scare last summer (much better now). She said many times she wanted to fly out to come help. I put her off until he was back on his feet then told her I would send her a ticket. Despite all those offers to help, she didnt take me up on the offer. After I couple weeks I realized she was in no shape to get herself together and fly out. So I told her I would fly a caregiver to come help her, and the care giver would be there in two days time. She protested I need more time etc. I wouldnt take no for an answer. The caregiver arrived and found conditions far, far worse than I could have imagined. I wont describe them, but imagine the worst. After a couple of days the caregiver managed to get her on the plane. The day after arriving I confronted her and told her she was out of control and needed help and that she needed inpatient rehab. I was relieved she didnt put up much resistance. Two days after starting rehab I was called and told she wanted to leave. Here comes the hard part for me. I arrived there and asked her where she wanted to go and she said back home with me and my husband. I said no, that was not an option. If she wanted to leave rehab I would buy her a plane ticket and take her to the airport. I said she could go back to living in squalor (I had not before spoken about how awful her conditions were at her home), I did not hold back. Somehow I calmly described how bad it was. She was shocked I would say she couldnt come back to our house. After an hour or so of tears and silence. She said okay, and went back in to the rehab facility. She stayed 60 days and now has been sober for 6 months. We helped her move across country to where we live. I share this because I finally faced it head on and it helped her decide to get help. She did all the hard work herself in recovery and so far it is really working for her.
Best of luck with your oldest. 💕