My little girl told me yesterday "mummy, sometimes I think you're not being yourself when daddy is around..it's like you're pretending to be happy to make him happy..and you always tell us to be true to ourselves and honest"!!
Holy shit, OP! How old is she?
Actually, regardless of her age, she doesn't need to see things like that. She certainly doesn't need to understand them. The fact that she knows you act differently around your husband - that you walk on eggshells in his presence, frankly - is teaching her Very Bad Things about relationships, about men, and especially about women.
I know people are always quick to swoop in, call LTB, and fly off again, but I really think it's time you at least consider it. Hopefully this unacceptable holiday behaviour is the catalyst you need to start at least thinking about what you would or could do if you left. He is abusing you, OP, and he is not far off from abusing your children and your parents, on top of that! I pray you can see this.
He may have generously raised your son as his own, but is this man - this abusive, frightening, aggressive, hateful, extremely unreasonable, overly critical, rude, thoughtless, selfish, and downright mean man - the kind of role model you want for your son? Is HE who you want YOUR SON TO BECOME one day? Is HE who you want YOUR DAUGHTER TO MARRY one day? Do you want them to continue learning - from both of you - that treating people the way he treats you (and your parents, and your children) is normal and acceptable??
This man may be financially supportive, but he doesn't seem to be supportive in ANY other way. He is not good for you, and he is certainly not good for your children. He may not have turned his abuse directly onto your DC in exactly the same way he has done you, but even acting the way he does toward you in front of them is horrible for their development, and - frankly - it's really only a matter of time until he does begin treating them the way he treats you.
Abusers (which, if HALF of what you're saying here is true, HE IS) very often tend to have that "perfect gentleman" side, to be perfectly capable of loving and even extremely kind and generous things. I can tell you that mine was extremely charming, very quick to smile and laugh, genuinely sweet, and surprisingly good natured - when he wanted to be. The rest of the time he was busy trying to strangle me to death and tear my face apart with his bare hands while telling me that I, somehow, was the imperfect and useless one... But he was "soooo sweet" that people rarely believed the truth about him, even when they witnessed it with their very own eyes.
Please, PLEASE, at least think about what you would do if you left. Look into your options. Find out from a solicitor - or a friend who has been through it, or others here on MN, or somebody if you're not yet ready to take the solicitor step - what your options are. I think you may be surprised. After this wretched holiday is over, talk to your parents, who have witnessed this first hand, and get their opinions. Ask them about what they've seen, and ask them to tell you honestly what they think about it. Help is out there, so take advantage of it. Please. At least start thinking about going, and taking your poor children with you. You owe it to them, to their futures.