Hey,
I'm on the run but just wanted to let you know that you will find people here who understand.
The thing that came to my mind immediately is that regardless of what he says, this is not about you. He's not drinking because of you and he's not leaving-to-sober-up because of you.
It's all him.
And the fact that he's scared and wants to figure his life out may actually be a very good thing.
Either way - I understand it must be a shock for him to just leave like that. I hope it means somehow that you and your daughter get a bit more peace and quiet.