Ingles2, do you have to be the adult who copes? Could you tell your dh that it's all a bit much, and maybe cut back on something? Eg. Seeing the pil quite so much.
Your family life does sound hard atm. And the money stuff must be a big pressure.
In the long run, it will be fine. My pil live in Europe, one for a lot of the year, one for pretty much all of it. It has its advantages, especially as the dc grow up. Lots of holidays. And they increasingly talk about us sending the dc over, without us!! Though I'm not ready for that yet!
It must be a shock. I suspect my dh sometimes feels a little abandoned, even now. Even though it is irrational.
My parents live in England, but not close. Though they are helping massively atm with holidays. Mind you, that wasn't the case when the dc were small (though that was my choice, too).
They do love you. (Trite thing to say, but they do.) And they must know you're finding it tough. I'm guessing your mum in particular has been longing to do this for years. And it's wonderful she's doing it. Imagine the guilt if she was sitting at your kitchen table, ten years hence, weeping that she had lost her life's horizons in some dream of subservience to her dc. You'd hate that. And it would make your heart shrink with fear at the prospect of your own future.
On the plus side, your parents clearly look at you, and see a woman who can deal with stuff, and that they've raised to be strong and independent, and capable of loving and raising her own dc.
Which, clearly, can have its downsides but ... at the same time, is a compliment.