People always say to, "Go f*ck yourself". But, if you f*ck yourself, is it sex or masturbation? Because it's self-pleasure, I'm leaning towards masturbation.
"To ****" essentially means to have sexual intercourse with. "Go **** yourself" therefore means have sexual intercourse with yourself; since masturbation is simply giving oneself sexual pleasure it is truly not "****ing yourself". To **** yourself would require some sort of penetration.
****ing yourself is mainly taking some inanimate object that has a hole; and putting your penis in and out of. Maybe.