What was Brent trying to do when he hit Lea in the novel, Whirligig?

While at a party, Brent is humiliated by Brianna, the one girl he wants to impress. He loses control of himself, swings a fist at his host, and leaves the party in humiliation and despair. Brent then gets on the wrong expressway with no idea how to get home, and he wallows in self-pity. Reason flees and the humiliation he anticipates from classmates on Monday morning cloud his thinking. Deciding on suicide, he takes his hands from the wheel of his car. Instead of ending his own life, he ends the life of eighteen-year-old Lea Zamora.