I think you're paralysed by thinking there's a 'perfect' way of doing this, that at some point you will have amassed enough money/paperwork etc and 'considered' your decidion enough that it will all just happen painlessly without 'mess'.
It's going to be painful and messy whenever you do it, and only going to get more so the longer you leave it. The situation has now escalated to the point where he is violent towards you. Once that boundary has been crossed its very unlikely that it won't happen again, this is how it happens, pushing a little bit further every time.
I know you keep saying on the thread 'I don't want this, I don't want this to be our lives' and that's perfectly understandable, but the fact is that this IS your lives. It will be, and worse too, until you change it. You are allowing your daughter to stay in this situation.
I'm an adult child of an alcoholic father. Lovely and caring most of the time. Could go months with things fine. I loved him. If my mum had asked if I wanted to leave I'd have said no. Because I was a child and I didn't know any better, wasn't equipped to make that decision. My mum was scared of disrupting our lives, thought that stability and the fact that the good days were more frequent than the bad meant that it made more sense to stay. Thought she could manage the situation and protect me from the worse. I loved my dad but I spent my entire childhood in fear. The good times were never really that good because I could never trust them to last. My mum thought she was managing the situation by getting me out of the way, but that just meant I sat terrified and confused in my bedroom. But of course I tried to act unaffected, I didn't want to upset my mum! I used to beg friends to stay over because I knew he would 'behave' better if they were there. I used to try so hard to be so perfect, so strong for my mum, so good and quiet and clever and do well at school and try to 'perform' for him or distract him somehow in the hope that I could head off whatever horribleness was coming. I used to come home from school and not be able to relax or get on with my evening until I ascertained what kind of mood everyone was in, my heart would sink if I saw he'd been drinking, and I was far too good at recognising the signs at such a young age.
This situation is causing untold damage to you and your daughter. It's incredibly hard for you I know but you need to stop waiting for the 'perfect' time to leave, you need to step up and protect your daughter now.