I think that you should have a straight talk with your DD, after which you should go.
I don't think that she is horrible, I doubt that you would agree with that either?
I think that she is trying, to control you so you show her that you do love her, even though you left when she was eight.
This sort of unreasonableness is common in children towards their Mothers who leave, when the child is around that age, especially if their resident parent hasn't helped them get through their hurt.
Nothing can make up for her being left and life changing again when your second marriage ended, she can't get those years back, when she was a child trying to understand why her world turned upside down.
Do the pair of you speak honestly?
I have adult children, tbh, I wouldn't emigrate, but I had a happy marriage until I was widowed, so I understand why you want this shot at happiness.
Times were different when you had your children, I can understand why you made the decisions that you did.
I don't think that you staying would solve her issues, you can't undo the past.
It is a sensitive situation, I have had them in my wider family and I've never quite understood the need for adults to take things onto FB, tbh.
So on that point, your DH should of kept his sentiments about looking forward to you joining him to private messages, for your Grandsons sake, as well, who I'm sure will miss you being a constant in his life.
The good thing about FB is that it is a chronology of the years, pictures, events don't get lost, unlike photos.