Your oldest knows his mother has a substance abuse problem and can be abusive.
The fact that you and your children lived your lives around her substance abuse as well as whatever her mental illness makes her unpredictable has traumatized you. Your children deserve to have boundaries and feel safe. It’s not right that you only get to enjoy a kind of normal at your wife’s whim.
Her showing up with promises reminds me of bipolar mania tbh. Then she gets depressive and mean?