I stayed for 5 years of progressively worse "bad nights", belligerence, passing out all over the house, waking up me and the kids, dangerous, neglectful behavior.
Nothing I said or did showed my ex that I was "serious" because he was (and still is) in such massive denial. When I finally left and he invented a narrative about why that had nothing to do with alcohol. He recently fought me in court over unsupervised visits with our son and lost. He has a long list of requirements to satisfy- alcohol treatment, etc. before any visits take place. He is acting like it never happened and saying things like, "I'll see DS this summer for 6 weeks" with no mention of the restrictions or following the court order. If I had stayed where I was, we would still be caught in the same back and forth dance, me making threats, maybe taking the kids to stay with his parents for a few days after a really bad incident, his dad dragging him to an AA meeting here and there.
When you say you're "serious about not putting up with this anymore" what does that actually mean? Are you planning to leave or divorce him? Part of the reason my ex never took my threats seriously is because they were empty ones. I said I was "done" thousands of times, threatened to leave thousands more. But I only followed through once. All of my threats were really just attempts to manipulate him into treatment. I didn't want or intend to actually leave, I just wanted him to get help. He didn't want to do that and had no intention of changing. I finally had to start making plans for myself and my children that didn't involve him getting sober, because it wasn't something I could count on and I had to stop acting like it was inevitable.
Have you looked into attending Al-Anon meetings? That's a good place to find support from people who are or have been in your shoes. It's free and many areas have at least one meeting every day so you can try several different ones. I know that having very young children and being pregnant while living with alcoholism is a nightmare. I hope you're able to get some real life support in addition to this site.
Glad you reached out here. Please keep reading and posting.