Trey'quan shows up at potentially the worst time since Janelle just learned she didn't get into Howard. But, luckily, he shows himself to be a decent guy and doesn't take advantage of her.
The main casualty is Janelle, who already emotional, gets into an argument with Pat that leads to, with Mildred egging her on, Ms. Pat smacking Janelle.
As shown by this episode, a lot of trauma that you think is dead and buried, can rise up like a weed and suck the life out of all you think has thrived despite your past and your family's.
And like Trayq'uan, things from your past will find the perfect time to show up and you can either handle it with grace like Janelle, or let your demons speak through you like Ms. Pat.