Además, si estás enamorado y no te dan bolilla...
Besides, if you're in love and the other one doesn't give you a second thought...
es como un piedrazo en la cabeza.
it's like getting hit on the head with a rock.
Captions 29-30, Verano Eterno - Fiesta GrandePlay Caption
That's gotta hurt. In Spanish, the suffix azo can signify a blow by the object at the root of the word. So, piedrazo means a blow by a piedra, or stone. By this logic:
Bala -> "bullet"
Balazo -> "blow by a bullet; a gunshot wound."
Codo -> "elbow"
Codazo -> "blow by an elbow; nudge."