hey there, I think you are doing really well in a horrible situation.
good plan on the bag, I had one for about a year at the end,, I also had a plan about how I would do it if X or Y happened having been in a situation where I tried to leave and was prevented, that helps with feeling you would be able to follow through. I was preevnted because AH snatched our son from my arms, screaming that he was going to tear my face off, and then took him to bed. I wasn't prepared for that, and didn't know what to do. My plan after that was that I would leave the house, and call the police immediately, which sounds simple, but in the immediacy of that situation I was unable to process what I could do, and I cowered in my room waiting for him to pass out and then took my son back, but was so defeated, exhausted and scared by that time, I couldn't go.
re the disease thing, it was part of what kept me stuck for ages (and I don't really accept it now, because although I think it helps recovering alcoholics to accept a disease model I think it can be peculiarly unhelpful to those around them), my most helpful analogy was if he had schizophrenia and refused to seek help and take his meds, would I stay whilst he was dangerous, verbally abusive and erratic, or would I accept that I could not support/love him into wellness?