Alcoholism is real, and it is a real disease. There's a difference between people who like to drink occasionally and those who can't stop. Brain chemistry causes the problem. So, it's not as easy as just drawing a line and not going over it. Everyone has to find a way to stop, and that will be different for some than others. Obviously, some people find a way to beat this disease.
Here are three stories from my own life:
1) I had a younger cousin who had all kinds of substance abuse problems, including alcohol. Eventually he was arrested for a second time for producing meth, and he went to jail for what was to be a 15 year sentence. He didn't make it one year...hung himself in the prison.
2) My wife has a cousin who secretly (really, no one in the family knew) had a major drinking problem. We found out because he was admitted to the hospital with liver failure and immediately put on a liver transplant list. Well, THAT was the wakeup call he needed. His liver has recovered, he is no longer on a transplant list, and he hasn't had a drop to drink in over 5 years.
3) Former bandmate of mine was a raging alcoholic. He turned to Karate and is now a personal trainer and Karate instructor. He has been sober for 30 years.
Alcoholism will kill you one way or another. Hopefully you don't take another life with you.
You need to try again, even if it's the same program you've taken before. Good luck to you.