Complex sentence: Russ tells Rusty that his father's outburst was because his dad was sad, and afraid of not knowing how to raise him alone, also that Rusty was not responsible for his mother's death.
Split into simpler sentences: Russ tells Rusty that his father's outburst was because his dad was upset, and scared that he didn't know how to raise his son alone. Russ also assures Rusty that he was not responsible for his mother's death.