When do you know its over?

Ive been with my husband for 3 years only, we have two boys together. Lately things have been crazy between us. He is a sober alcoholic and do occasional substance abuse. i am finding our relationship drifting away each day. We've been verbally abusive to each other. At first calling him names back when he attacked me would be my defense. Then i realized it made me feel like crap so i stopped and just let him do it. ive voice my concern to him and how his abuse is putting a wall between us but nothing change. His new thing is video chatting with random girls over the internet via this app call "houseparty: he will spend all night i like till 4am inside the garage. so i guess mu question is do i stay or do i leave. ive given him alot of opportunities. Hes had alot of wake uf calls, like DUI, but he wont admit his drinking issues. How do you know its over?