Complex sentence: Monica finally earns the starting point guard spot at the end of the season, Quincy can't be happy for her because he blames her for not being there for him when he was having problems with his father.
Split into simpler sentences: Monica finally earns the starting point guard spot at the end of the season. However, Quincy can't be happy for her, because he blames her for not being there for him when he was having problems with his father.