I just wanted to say that Sueby brings up a really good point (well many), but about talking about it. It's not a secret, well certainly not your secret. You have been isolated (this is common). He told you to refuse help from your family and I'm sure you have lost touch with many people. Reach out to them, reconnect. It will be so freeing.
• I haven’t talked to anyone about the problem for years, last week was the first time I opened up about it to a friend who is the daughter of an alcoholic;
This sounds like someone who will really understand.
You also have us now, we are here to listen and support you as well. You're not alone.