What b.s. I can totally understand your frustration. It's so totally unfair that you get married, plan a family together and the alcoholic spouse infiltrates the dream you thought you both shared, with HIS addiction. It's so selfish. And after the many years of damage is done and they decide to get sober, surprise, he's going to leave.
I know you're going to have a ton of emotions to go through. I think if I were you, I'd try to work through the resentment with the counselor so that you can look forward to the peace and sanity you will have when the split is over.
My AH also says it always comes back to his drinking. Yeah, no kidding. Funny how your AH says it's in the children's best interest not to bring up his drinking in court. Boy, he really wants his cake and to eat it too. 8 months combined with the stress of a divorce sounds ripe for a relapse to me. Like you'd keep that secret from the courts?? For what reason? For all you know, he's having cravings like crazy and could be planning the day when you're gone so he can drink and pee freely.
His priority has been booze for all these years. Convenient that he had someone around to put the kids first. Now he wants 50/50 after 8 months of sobriety? Sounds equally selfish to me. I'd be just as ticked and hurt if it happened to me. Get a good lawyer.