For some alcoholics it can be a breakthrough, others use it as an excuse. Your mother seems like she is the latter.
When I was in active addiction, I thought I was hopeless, lazy, incapable etc because I couldn’t manage to stop drinking because I always ended up with a drink in my hand. My mind had convinced me it was fine and as such, I accepted I must just be an incapable person and an alcoholic was just who I was, my personality, I couldn’t escape it. Once someone at AA told me it was a disease I felt like I had something to fight against, something to cure, it wasn’t me it was something wrong with me that I could fix. This was only because I wanted to get better though, I’d wanted to stop drinking long before I managed to.
The flip side is some alcoholics hear “disease” and just completely surrender to it. They seem to think there’s nothing they can do and it’s out of their control as it’s a disease so it’s not their responsibility to fix. This is completely incorrect and it sounds as if your mother sees it this way - she has a disease so it’s not her fault if she starts drinking again, when it really is her decision to make.
I also completely understand from your side, hearing it called a “disease” must be ridiculously frustrating because people with diseases usually want to get better, not make themselves worse. I saw it more as an allergic reaction to alcohol, I didn’t deal with alcohol in the same way others did, my friends could have one or two but once I had one, a switch flicked in my brain and I couldn’t stop. I didn’t feel diseased but I knew I was fighting against something. I found it more of a struggle mentally than anything else.
For me, there is a difference between drinking during active addiction and relapsing during sobriety. Drinking during active addiction is incredibly hard to stop BUT it is possible. You did everything you could to make this possible for your mother. Once someone has started their sobriety and has broken away from the claws of their addictive brain, and has maintained that sobriety for some time, they do have a choice whether or not the decide to start drinking again, much more so than in active addiction. Whether it’s the addiction or their own free will, she had a choice to make which wasn’t clouded by inebriation and she chose alcohol. That is no reflection on you or her children, addicts choose their substance over everything until they finally, genuinely decide they need to change. Some addicts never decide this, whether it’s due to denial or inability, but it’s still a choice.
Your mother is clearly deeply addicted to alcohol and it doesn’t sound like she wants to help herself which is the only way alcoholics can stay dedicated enough to remain sober. Please don’t see this as any fault by yourself, you sound as if you’ve done more than your fair share in trying to help her and have given her plenty of opportunities but if she cannot continuously put the work in herself, she won’t remain sober. Going NC is the best thing you can do OP, therapy rather than Al Anon is a great idea to take the focus away from alcoholism and to build yourself back up, but I really wouldn’t contact your mother again. I really wish you the best, I’ve recently supported my partner though something similar and he also chose NC. He has saved himself a lot of stress and heartache and I really hope you’re able to find peace in knowing you did all you could but had to step back to protect yourself and your children x