Hmm, I truly don't think its prolactin induced. Estrogen related gyno tends to form a hard lump under the nipple, sore to pinch. Prolactin causes more of a sore knot, not extremely hard like a marble. Prolactin tends to make the nips puffy as well.
If it's prolactin based, something like lights out for the l-dopa + some vit b6 can help, and if its estrogen, you will love the new updated intimidate SRT that will be released