I assume somebody will have suggested the Freedom Programme to you? (Www.freedomprogramme.co.uk) They would answer that question.
You don't understand his reasoning or his moods because he's not operating in normal ways like you or I, he's coming at this from an abuser's perspective.
His moods change at the drop of a hat because his "anger" is fake, it's manufactured, it's a tool he uses to hurt you and to make you do what he wants. He keeps you spinning, trying to keep up with him, rushing around on his eggshells trying to work out what he's thinking and what he's going to do next, trying to stop him kicking off. Which means you don't get the chance to step back and look objectively at what he's doing.
His reasoning is based on his belief that you exist to meet his needs, you aren't a person you are an object that serves him, and you must do what he wants. When you stand up to him, think for yourself, challenge him, don't do what he wants, seem too confident or happy, you're breaking his rules and he needs to bring you back in line. That's when the moods arrive.
He will always, always, always put it back on you, no matter how reasonable you are, no matter how perfect you try to be, there is nothing you can do to get a different outcome. He needs you to believe it's your fault and there is something you could do to make him stop being "angry" because that is how he stops you leaving. You stick around forever trying to "fix" the impossible.
He wants to stop you leaving because he believes he owns you and he wants you there to serve him. The only person he loves is himself.
Do you love yourself? Even a tiny bit?
You sound exhausted and at breaking point. Wouldn't it be better to leave with your children permanently, and not have to deal with this shit from him anymore? Think how much more energy you would have without him dragging you down into the abyss.
I know it hurts to face, but the part of him that drew you in originally, the kind loving person you fell in love with, does not exist. That person was an act, a lure on a fishing line. You'll spend the rest of your life trying to make him happy to get that person back and you'll never achieve it, because it wasn't real. It's yet another way for him to entrap you. The real him is the one who hurts you and exhausts you and who makes you dread going home.
There is part of you fighting still, that spark that took you out the house today. Now use it to get this sorted for good.
You can do it.
I'm sure you have the number, but 0808 2000 247.
Www.freedomprogramme.co.uk
It doesn't have to be like this.