Complex sentence: Blyton's situation was made worse with the declining of her husband's health through the 1960s, suffering from severe arthritis in his neck and hips, deafness, and he became increasingly ill-tempered and erratic until his death in 1967.
Split into simpler sentences: Blyton's situation was made worse with the declining of her husband's health throughout the 1960s. Darrel Waters suffered from severe arthritis in his neck and hips, deafness, and he became increasingly ill-tempered and erratic until his death in 1967.