first of all welcome to the site. I'm sorry to hear the pain you're in but congrats on being pregnant, I'm sorry to hear that you're going through such a hard time with your husband. A lot of different things caught my eye when I was reading your story. Your husband is showing all signs of addiction getting worst and worst. He is blaming everything on you because that's what addicts do.
This is hard to accept but addiction is a disease. It is something they can not control especially when they are actively in it. you say his dad goes to NA and he is sober and clean, but you don't want to be with someone who has to do that, but unfortunately your husband will need meetings and a 12 step program to have any chance at a normal life again. It's a life long progressive that only gets worst if not treated.
But here's the other hard part, you are not able to make him want to change. The yelling, fighting, or screaming will only make him feel worst and sadly love will not get them to stay clean either. He has to want to change.
The best thing you can do for yourself is start going to meetings. my xbf used drugs and drank and I personally like al anon more than I liked nar anon but everyone has their own preference. I know he's the one with the problem, but sadly addiction is a family disease and you will need to start focusing on yourself too because you have issues too that you need to work on to have a happier life.
I know this is all overwhelming and when you say you want 4 kids and you won't find anyone else, that is definitely not true. You have to believe that someone worthy will love you again and you're children. no one ever wants to break up their families but you have to do what's best for you and your kids especially if you're husband never gets clean.
And also, it's hard to make friends of course, but you have to give yourself a chance to make friends, and if u go to meetings there are amazing ppl who will be your friend and be there for you too. They know what you've been through. Don't isolate yourself, be kind to yourself, and feel free to private message anytime if you need to talk to someone. you're in my prayers. God bless