@Userccjlnhibibljn8 I'm sorry. I think my dad feels a lot like you do. He can't help feeling guilty, thinking about how he should have done more. Or should have done less.
I think you know, rationally, that you did all you could. My dad knows that too. But as pointythings says, the feelings are just so powerful.
We are a little bit further along than you, as it's almost a year for us. The first year is such a lot, I think. I've heard the second year isn't fabulous either. But I reckon more clarity comes.
(I'm currently reading a lot about alcoholism, emotionally absent parenting etc. And I'm speaking to family members on my mum's side to find out more about what happened, how things went wrong, family history, why they're all so fucking odd. I guess I'm still in fact-finding mode, but I think in a calm, reflective way. I'll list the books I've read, at some point, as that might be useful for the other folks here with alcoholic parents.)