I'm so sorry you're dealing with this.
I grew up with an alcoholic father and so much of what you're saying rings true.
You sound like you're at the point I reached on my wedding day. It's a point where you're just so unutterably, unbearably sad and tired. Dad had relapsed a few times, having managed to get dry for a year or two here and there and, to my knowledge, he was in a dry spell. I walked towards him at the top of the aisle, ready for him to walk me down and I could smell the whiskey before I reached him. I could see that telltale glaze in his eyes, the slightly happy, sozzled smile. And I just smiled and fixed it there, feeling like I'd been punched in the gut. I didn't want a single thing on my wedding day. No favours or a big dress or princessy moments or anything. I just wanted to get married and my Dad to witness it, not a drunk. I wanted to curl up in a ball and sob. The logical part of my brain knew he was nervous and struggling with the magnitude of the day and I wanted to forgive him. Emotionally, I wanted to scream.
Actually, it was a turning point. After my honeymoon I ended up going to my Dad's, ostensibly just to call in but that moment on my wedding day had lit a fuse and I said all the things I should have said before. Mostly that I was fucking terrified. That I loved him and I understood. But I couldn't do it anymore. I couldn't live in fear of alcohol and its death grip on my whole life. I cried and cried. I never, ever cry. I am a calm, steadfast, grin and bear it type. Not that day though.
Things were bad for a while. I didn't know it at the time but he was heading for a psychotic episode and three months after I got married, on my paternal grandmother's 80th birthday, he was sectioned. It was the best thing that ever happened to him. Instead of being treated for depression, they finally diagnosed him as having bipolar disorder and they started to treat it.
Ten years later and my Dad hasn't touched alcohol since. He is a different man. He is a loving, devoted grandfather and I am so very proud of the person he is. The person he always was I guess, just battling a demon.
I know so well that feeling of knowing they're not at rock bottom but wishing they could be so at least there's a chance of rebuilding. On the way down, they're just stuck aren't they? It's fucking awful. The years I wasted thinking why. Just WHY. Why does alcohol have that power and his children and wife and his life can't match it. Why am I not good enough for him to want to be my sober dad? It's a bastard of a disease.
My Dad told me the other day he never actually liked drinking. The taste that is. Said he always hated it. I burst into tears completely out of the blue. Bloody alcohol.