Dd and sil are probably just very tired and need a break themselves. However, still, as pps have said, they have no right to expect this of you, no right to expect childminding of you at all. Kind of you to even try, it proved too difficult, you can't do it anymore, end of story.
It caught my attention, however, that dd accuses you of "always changing your mind." Is it possible you agreed wholeheartedly to this idea at first and then reneged after that exhausting weekend? I don't blame you for changing your mind after that, but it would have been better to have said, "I'll try it and see how it goes."
But oh well. Unless you signed a contract, lol, you are under no obligation to do this. Dd and family are lucky that you've done as much as you have. True, they may get mad and keep dgd from staying with you, but is that worse than having to endure more exhausting weekends? You may have to be willing to trade off what you enjoy to avoid what you don't enjoy. Hope it all gets sorted out in the end.
Baby Reindeer - anyone watched it?
Alphabetical girls and boys names January 2024