Macrophallus - "An Inordinately Large Penis." See "macro-" and "phallus."
Macro- - "Large" From the Greek "makro-" from "makros" = "large."
Phallus - "Penis; A Representation of the Penis." From the Greek "phallos" = "phallus."
Macrophallus is also synonymous with Macropenis which means an abnormally large penis.
And to answer your question, yes I had the same problem but mine was caused by a pituitary tumor, surgery helped slow it down and get my hormones in better balance.