Pressure has to go somewhere, and it usually goes to whoever is nearest. Money trouble gets said out loud as a remark about the dishwasher. Fear about a diagnosis comes out as sharpness at a fifteen-year-old.
Things said in the worst month are difficult to unsay, which is an argument for putting a gap between the feeling and the sentence. Not swallowing it. Naming what it's actually about, out loud, to the person: this isn't about the dishwasher.