Al-anon would be a great place for you and will help you learn to accept that there is very little YOU can do if she is just not ready to stop. It will help you figure out the direction in life you want to take.
I am a firm believer that history doesn't repeat itself, people repeat history.
I'm betting my bottom dollar that alcohol played a major part in the ending of her other relationship. You met her while she was still all tangled up in a marriage where the ending was all his fault ( alcoholics love to deflect and blame).
She lived in her place while you lived in yours so she was able to drink and probably hide a good portion of it from you until you married.
If she's up drinking all night how is she able to work and support herself and her habit?
Not trying to be negative just real and really knowing how alcoholics operate.