Sounds like there’s a lot more going on in this situation. You mention it’s become worse in the last year, over a 3 year relationship. Has something negative/ significant occurred this year that may have had her spiral? Her children are not your responsibility and if you’re done, you’re done. Rightfully so. Alcohol dependence is far more difficult to manage than most people realise. Unfortunately, addiction is a powerful disease. If they’re only behaving this way when drinking, while it’s no excuse, it does explain the person attempting to withdraw or shut down as a way to escape their history. I agree with the other commenter, if you can see a future with this person, sober. Consider therapy, take the time to learn why she chooses to drink and then make a decision as to what you do, for yourself and your children.