Someone encourage me to divorce

I’m 30 and me and my husband have been together since we were 18 years old. Ever since we’ve gotten together, he’s been an alcoholic but when we were younger I thought maybe it was just a phase. But it definitely isn’t! We have 3 small kids (6,4, and 3) and my husband is a gamer so he will stay up all night till 6-7am drinking and I work from home so he stays asleep all afternoon and then if I wake him up to watch the kids, he will return back to the couch and sleep some more. About a year ago it was really bad when we were supposed to have a family outing for Easter and he stayed up until 12:30pm that afternoon and was drunk calling me all sorts of names and spent the holiday by myself with the kids. At that time I did mess up and had an affair with an old high school friend and he knows this but for some reason I know I need to divorce my husband but I just can’t work up the courage. My husband still hasn’t changed, he stills very sneaky with his alcohol and he’s just a slob in addition to that. He doesn’t help clean for anything. I asked him two months ago to clean the bathrooms and he never did and they sat like that for those 2 months filled with trash and brown toilets. It’s embarrassing and writing this out makes me feel stupid to ask when I should obviously divorce but I just can’t make the first step. 🥲