You know, being an alcoholic -is- lonely. And while we're still in the same space as the alcoholic (feeling -totally- alone, as it happens) we allow them to pretend that that loneliness isn't part and parcel of the disease.
You felt lonely in the relationship. He's feeling lonely now. It's a lonely disease, on both sides - so much isolation.
But you won't get a clear view of what the relationship even was (or how lonely it was for you) until you're surrounded with healthy people who can relate in a give and take, healthy way.
And when he's really alone with that bottle - he stands a much better chance of getting his own clear picture of where his drinking has taken him.
It is hard but I promise it gets easier - and the most important thing is that being a child in that environment is the loneliest thing of all. You've given your daughter the gift of getting her out of there and it will get easier, and better.
What you did took guts and strength, it may just be the best thing for everyone - even though it might not feel like it. Barb's right - you're where you should be because that's where you are.
Hugs and prayers,
SL.