AIO for cancelling my wedding?

This is my second post about this because I’m having trouble navigating it. I (28F) have been with my (28M) partner for 4 years. We moved in after being together for 2 years and I noticed he had an affinity for alcohol but didn’t see it as a problem (yet), but definitely noted it as strange. Last year his mother passed away but before, while she was sick he got drunk and totaled his car. Because of this incident after she passed I told him to be aware of his emotions and do his best to have a better outlet than drinking (something like therapy). A month later he binged and got black out and came home 6 am peed on the floor and missed his entire day of work. After this incident he said he wouldn’t drink again, said he’d get therapy (only went 4 times then quit). Things were o.k. for a while then December comes and he comes home black out again, pees on the floor and turns on burners in the kitchen, then proceeds to fall asleep while standing up.

Our wedding was supposed to happen in March and I knew things wouldn’t be fixed by then (shocker) so I told him I couldn’t marry him and cancelled it. In truth I don’t see how we can come back from this. I think he’s a great man but has things he needs to work through that I can’t do for him. I don’t know what it’s like to lose a parent and I can’t relate to how he is emotionally responding to what he’s going through. But I will say, disappointedly he is still going to his bachelors party — he said he won’t drink this year with the caveat being the Bach which just tells me everything I need to know about his mental state. Anyway, any advice helps.