lockdown He is saying that (the leaving him/divorce thing and hurting the DS) to intimidate you into staying. It's what terrifies HIM. That you will go, leaving him.
SO... OWN THAT POWER.
Put it this way. Unless things RADICALLY change, you need to leave, you know that, we know that, anyone with half a brain would know that.
TELL your H, that you WILL divorce him, and he'll lose BOTH you and DS. Remind him that you WILL be Ooooh, SO MUCH happier on your own, NOT being bullied, talked down to, moaned at, criticised, pawed at.
In time you will find a GOOD man, one that WILL treat you properly, and raise your son to be a good man... Tell him that unless he is planning a complete 180 degree shift in his behaviour right now, that he'd better start packing, so that the day that you find Mr OhSoMuchBetter comes sooner. Every day that this H of yours is in your life is a day that the right man ISN'T.
That usually stings em really hard.
Your H knows you practically are calling him abusive to his face, he seems to even recognise it, but is CHOOSING not to stop.
You need to be strong, and NOT allow his abuse of you anymore. Call him out on everything. Yes it's hideous, yes you feel like a school marm but for the love of God, what IS the alternative?
As far as he is concerned, the alternative is that if he ignores it, eventually you will give up your little crusade and let him go back to the way thins were... but they will of course only get worse as his desire/need for a fix of control needs satisfying.