OP, my DH is also away at the moment. I do not have any DC - my DC will not be getting or expecting a spotless house when he gets home. And although I will cook for him, it will be a nice surprise and will be appreciated. This is normal, fair marriage.
If you are not able to have the 2 booked holidays, you cancel them both and arrange something for the whole family within budget - sun £10 holiday / camping / caravan etc. One person doesn't take both holidays for himself!
He is spectacularly selfish, and it is amazing to me that you are asking for outside opinions on this.
If the debts are half hours, so is any spare money. So he doesn't get first pick of any money for toys or holidays.
I suspect that your family see you as 'woe is me' because you ensure that he is always portrayed as a great man, because you love him and want everyone to love him too. If they knew the full story, they'd think he was a prick just as we do.
Stop asking / negotiating. Tell him what is happening. You are taking some time for yourself, you are not running around like a headless chicken doing the cleaning. And if he doesn't like it? You will leave, he will have to clean and cook for himself, pay you maintenance, you will no longer help him build up debt, and he will need to set aside time for contact with his children.
Be tough OP