Welcome aboard LilGirl.
I just thought I'd chime in. Both my parents were "functional" alcoholics. My father had an exceedingly successful career, he's now retired. My mom was a stay at home mom who managed to make things seem outwardly that we were the model of the Cleaver's.
You stated in your first post that your life is better without your father coming in and creating a destructive swath through your heart. And that you'd told him you weren't going to speak to him again. Well, I say it's time to defend that boundary.
He calls and leaves voicemails. If possible, I say delete them without listening to them. He has the right to behave as he feels appropriate. You have the right to refuse his treatment of you. You have the ability to walk away, to not listen to the voicemails, to move forward with your life.
ACoAs are very good at feeling guilty. My husband once asked me if I felt guilty when it rained. I said "sometimes". Yeah. Do I have any control over the rain? No. Do you have any control over your father? No. Feeling guilty about removing yourself from his toxic ways makes about as much sense as feeling guilty about carrying an umbrella when it's raining.
You need to protect you. You also need to protect your children and stop the cycle if you possibly can.
I have not fully detached from my parents, but I don't talk to them when they're drunk either. I tell them I have to go and I'll call them later (usually early enough that they haven't started drinking yet). I interact via email. I make sure that, if I do visit them, I have set up an 'escape plan'.
While most who know me would say I am kind and giving and generous, when it comes to my parents, I am very very selfish. I am finally learning how to be selfish. I will not tolerate the crap anymore. I will not deal with the lies and falsehoods. I hang up on them when they call drunk. I don't believe them when they say positive things. I can now (after much therapy and the support of a wonderful husband) laugh at the ludicrousness of the situations. It's not a funny laugh, more of a pathetic one, but I see there's humor in the insanity that is my parents. Gallows humor, but humor still.
I don't know if any of this early morning rambling will help you or not. Suffice to say you're not alone. Everyone takes their own path to healing, some need to completely detach, some learn to set and defend boundaries, some learn to put up an emotional shield and let it roll off.
It's okay to be selfish when being selfish protects you. If it helps, I not only give you my permission to be selfish, but strongly encourage you to do so. You can't take good care of anyone else if you, yourself, are not taken care of. So put yourself where you should be - in that number 1 spot. Take care of yourself so you can take care of your children. Take care of yourself so you can be there for your husband. Let your father take care of himself in whatever style he chooses, but try not to get sucked into his demented world. It's not a world you want to live in, and you're a grownup now. You don't have to live in his world anymore.