Yeah thats sucks man, how long did you run the letro for? You should had stayed at 2.5mg for a while until the symptoms disappeared. I think at least the Letro would stop it from progressing if not completely remove it.
My bro got gyno, very small hard lump behind right nipple 3rd - 4th week H-drol. He only kept any eye on it throughout cycle, didn't use anything, and then ran his PCT. He did the same PCT as me and said size slightly reduced but is still there.
Is it large/visible?