FEM, you are not alone. My mother didn't like children. She didn't like her children either. She openly hated my older sister and sent her to the aunts in Louisiana every summer to get rid of her. She tolerated my older brother and ignored me. We grew up unloved and never knowing what it meant to have a loving mother.
When Mom had a stroke and wound up living with us, I went through the whole gamut of feelings. I did my best and I have no regrets. My sister never darkened my door. Not. One. Time. And I couldn't blame her. My brother passed away and Mom wanted to know why we were at his funeral. She just had no idea. Sad.
I was Daddy's girl, so I at least had one parent that loved me. He adopted my brother and sister, and he loved them too. But they never wanted to dig in the garden or do any of the things he liked to do.
All you can do is the best you can do. Take some time off from them, it sounds like you need it. You can't win with them anyway, they are being cared for, so don't feel guilty. You have to take care of yourself, you deserve happiness and if they are stealing your happiness, take a vacation from them. Their feelings for you are not going to change, no matter what you do. It just sucks and it isn't fair. But it sure made me a better parent and I made sure my kids were loved, felt loved, no matter what. And I'll bet that you were/are a fantastic Mom too.