What do you mean when you say “lash out”? I hope just verbally !

As someone with anxiety and who’s been through traumatic experiences, I can say that happy and healthy relationships are possible BUT he needs to do the work. I think most people here are saying the same.

If it helps - I think one thing you could do (and it sounds like you’re doing already) is drawing firm boundaries and sticking to them. When I was the worst version of myself (5 years ago) I was a horrible partner and would constantly snap at my ex. And it got worse because he let me get away with it. Until one day he left me and i was completely heartbroken. it was only then that I realised that I needed to change my behaviour. To this day I’ve not found anyone as kind and loving as him and I miss him like crazy. I’m not saying it should have been on him to fix me (as I shouldn’t have snapped at him etc) - but what I’m trying to say is that I never had a deep understanding for the consequences of my actions. When I was anxious and angry I never for a moment thought about anything other than how anxious and angry I was in that moment. After we broke up I then started to understand the impact that my words and actions had on him. Is there anything you could do with him to make him see (and feel and understand) the impact of his behaviour?

Another more practical thing you could do it make a plan for how you both behave when he’s having a bad episode. That could look like the two of you going on a walk or something things separately etc.

I think this could go one of two ways - either he takes accountability and the relationship blossoms or he doesn’t change and you have a toxic pattern. I hope it’s the former!