Complex sentence: She developed diabetes in the 1980s, a condition she struggled with (she said that she was the "world's worst diabetic") and as a result of which she was registered blind in 2001; she wove this theme into her work.
Split into simpler sentences: She developed diabetes in the 1980s, a condition she struggled with. She said that she was the "world's worst diabetic", as a result of which she was registered blind in 2001, and she wove this theme into her work.