For me ... active alcoholism led to the very predictable state of Pitiful & Incomprehensible Demoralization. It was not pretty.
It may be best to step back from it ... the closer you stand, the more likely for the ugliness to splatter on you and your daughter.
Turn to focus on the best you can do for you & her ... it may be the better alternative than looking at the ugliness, and inevitably getting splattered by it. Do not cast what you have of the 'Pearls' still available in your life, to your AH if he has chosen to run with the 'swine'.