To leave or to stay

Before any judgements I want to clarify that I am not the perfect wife nor do I excuse the negative things that we each have done. My husband is a terrific man in so many ways. He is sweet and funny and loving but he's always had the fatal flaw of self deprecation. He has always been harder on himself than anyone could ever be and I don't know if you've ever tried to love someone else like that but it's damn near impossible. He is mean and from time to time abusive because of how he views himself. Not justifying his behavior. Hes an alcoholic. And I feel like if I stay I will be one too because I don't know how to be sober when he's like this. I don't want to be like this all I keep thinking is that we used to be sober and happy and in love. Now I feel all that's left is the end and I can't do that but maybe I need to. My heart is torn and broken and shredded.