Complex sentence: In later years, Dunnery would himself succumb to heavy drinking and eventual alcoholism (overcoming his addiction in the early 1990s), and many of his songs would reference his struggles with alcoholism and the behaviour that surrounded it.
Split into simpler sentences: In later years, Dunnery would himself succumb to heavy drinking and eventual alcoholism. He overcame his addiction in the early 1990s, but many of his songs would reference his struggles with alcoholism and the behaviour that surrounded it.