I’ve seen people talk about actors and artists that had a terrible time.
My own would be Anne Rice. She wrote Interview with the Vampire after her young daughter died of Leukemia. Then her husband suddenly died of a brain hemorrhage. I suspect her Christian, anti-fanfic phase was a result of mental illness and manipulation from the publishers, although I don’t think she ever apologized.
Julie Powell - I wouldn’t call her a visionary, but I liked her work quite a bit. It was clear in her second book that she was a very troubled person, and it is a real shame she died so young.
Ditto Elizabeth Wurtzel, who - in my opinion - was a huge talent.
I read a lot of memoirs, though, and people very rarely write happy ones. One of my favourites is Her Last Death by Susanna Sonnenberg - if I do everything her mother didn’t (and vice versa) I know I will be a good mother.