Complex sentence: By 1964, his family life is empty and subsequently he is a workaholic, but displays signs of dissent, has not been promoted since 1954, and is unknowingly being watched by the Gestapo.
Split into simpler sentences: By 1964, his family life is empty and subsequently he is a workaholic. However, he displays signs of dissent, has not been promoted since 1954, and is unknowingly being watched by the Gestapo.