Presumably your ds's exams are over now, or will be by the end of this week. You should start making plans to separate by getting legal and financial advice.
Your dd may well prefer to live with your dh at first but the novelty would probably wear off when he gets fed up doing all the shopping, cleaning, cooking, housework, or she gets annoyed at being asked to pitch in.
Life without rules only works when there is someone else picking up the slack and at the moment that person is you. Take yourself out of the equation and they will both realise how much you've been doing and how you hold it all together.
But the main reason to separate would be to get your son away from this awful influence. It must be soul destroying to live with a father who largely ignores you. He may benefit from some counselling to help him understand that it's not his fault, it's nothing that he said or did, or didn't say and do. His father is 100% responsible for this.
Finally, for your own wellbeing, you need to get away from this man. Yes, his behaviour is abusive and a heart attack does not excuse it. He respects you 'sometimes'? No, he doesn't respect you at all. Start making plans to end this unhealthy dynamic.