Partner has relapsed after 4 months sober…

Some context: he had a very high profile, successful job as an airline captain.
When he stopped flying he started drinking, and was drinking a litre of vodka per day, most days, for around 6 years on and off. I was not aware of this problem despite knowing him for a few years.
We got together, and I’m teetotal. I then stopped him drinking many times, and he moved closer to be with me, and for 7 months he didn’t touch alcohol and didn’t crave it- in fact he hates the taste of it.
Then he started having relapses, of between 2 and 14 days. Maybe 16 relapses in 3 years.
When drunk he is very unpleasant: verbally abusive, throwing furniture, sending nasty messages, and he would throw me out of the house and I had to get a hotel or something. Once I slept in the car in winter.
Now we have a house each, as I won’t live together with this risk.
I have, with the support of a therapist, started setting boundaries. If he drinks I block him and won’t see him until he is 2 days clear. No more rescuing him and sobering him up.
March 6th was the end of his last relapse, and since then he had been great and we had a lovely time.
I then spent a few days away, and today, the day before I was due back, he has started drinking again. This is especially bad because his house is being renovated so he was staying with me and he knows there is a no drink rule.
I told him to get out of my house immediately and find a hotel and only contact me when he is sober, determined to stay that way and ready to talk about it.
It feels devastating after everything we have been through. We have both had considerable stress and trauma to deal with alongside this but I do not consider it an excuse for his behaviour and I am at the point where I cannot trust him to be there for me the way I’ve been for him. Any plans we make feel shaky because he might not be there, and I cannot rely on him like I need to. Also I’m autistic so I need stability and things not changing.
People say ‘just leave’ but it won’t stop me worrying about him- you can’t turn off caring about someone.
I’d like to have some hope…. he wasn’t alcoholic before he stopped flying but this is bad.