When to keep being there for addict spouse or when to call quits?

I’m going to try to keep it short but basically I am almost 30 and was born into a family of addicts. I have almost lost my brother to addiction (he is gratefully a year sober this month) but my father wasn’t as lucky who passed away after a long battle with addiction last year. SURPRISE SURPRISE. I always end up in relationships either with addicts or people with addicted family members- my boyfriend is both. He was abandoned by his mom and his dad lives on the street. He himself is an alcoholic but when we met he was working to get sober. We both have the goal and have put effort into maintaining sobriety- the best part of our relationship was the 6 months we were sober. After that we both sort of slipped up, I don’t consider myself an addict I just get extremely hungover and have the gene so I want to be sober for those reasons but his runs way deeper. The last 5 months have been weeks of amazing and then when one stressful thing occurs (which is a lot these days between his dad, new jobs for both of us, and in the middle of moving) he runs to the bottle. He is not physically but emotionally abusive when he drinks. He doesn’t yell, but accuses me of cheating and being unfaithful when I haven’t done a single thing our whole relationship for him to think that. He says I don’t love him. I make him feel worthless. I treat him like shit. None of which comes out when he’s sober. The next day is always the same- him embarrassed and apologizing and reassuring me he doesn’t actually feel that way. But it’s getting harder and harder to forgive. Anytime we have one disagreement and he is drinking he will just leave. Walk out the door and walk to the nearest bar. My question is where is the line where I can be a supportive partner and what sort of boundaries or dare I say ultimatums can be justified when dating someone who struggles? He is SUCH a good person. He cares for people deeply, but is so so so damaged. I’ve never met a single person who has been through as awful of things and when my father died I cannot express how much he was there for me. He took a week off work to lay in bed with me while I cried he made all the meals he let me scream in anger without judgement. His opinion is that this is a similar situation where he needs support and that kind of dedication from me but it’s hard with my past and baggage not to just be triggered and think I am just the cliche woman of emotionally unavailable alcoholic ending up with an emotionally turbulent alcoholic.

Side note I have talked to him about therapy and rehab and he seems open to both but no other steps have been made.