What a difficult situation for you both!
We are home educating, and have been from the beginning, so I can't give any turn around stories. I suspected school would not go well for my son.
You are not selfish for worrying about the intensity - any sane person would be

but remember that this might not be as bad when her other needs are being met as they are now. But you will need back up. If you are even thinking about home education, you could start to make contact with your local groups.
To respond to another concern you alluded to, I DO find the sole responsibility for their education overwhelming at times, particularly given their potential. But honestly, with a child at school, it might seem like the responsibility is shared, but it isn't really. Sorry

Home education just makes it more obvious.
I hope you can find something that will work for you and your daughter.