@plowey You have described situations that are very common...meaning son living with Mother and not the best situation....and the moving to be near a child and then the child moving.
When my brother lived with my Mother I was concerned and then another older person than I who had the same family situation (son living with Mother) asked me "Is his help sufficient." That helped me because it was sufficient compared to her having to be in a nursing home etc. Mother had emphysema and could hardly get out of bed. As long as a child who is living with a parent is not being abuse to their parent (physically, mentally and financially) and their help is sufficient....and as well keeps the parent from being alone in their home.....that is better than many other possible situations.
You did what you thought would be best for yourself with moving close to your daughter. Sometimes things we think are best for our children or ourselves backfire...it happens. Are you living in an area that has more positive aspects than where you were living. That is one of the questions you will probably have to answer. If you have lightened any aspect to your life's load with the move, that is positive. Personally I would make a two column list with the positives and negatives of the move or whatever you are thinking for yourself. But...we always have to give time to whatever we do. Getting over things and understanding all takes time, as we know.
Barbara

@plowey

If your mother and brother are both reasonably satisfied with their situation, I would let that be. If they don’t see a problem, and you haven’t seen actual evidence of abuse, there is no problem. So far as the daughter. I would admit to myself that I can’t control what she does next or 5 years from now. And so plan my life without her. If she’s around, it’s a plus. If not, life is still going to be good.

But it’s much more what you do now. I personally would evaluate the contacts I have outside my family. And compare them in the old and new places. Do I have contacts like church, friends, etc. in my old home that’s it’s worth returning for? Will they welcome me back? How congenial do the churches, civic groups, senior centers seem in this new home? Do I have the energy to make new friends?

Then I would look carefully at my finances. Can I afford a double move?

I am sorry you’re going through this. Sometimes there are no really good choices. Only the least bad choice. And that is what I hope you will be able to make.