Because of "Apphia"'s Greek appearance, I believe that you could get by with using it (granted, you also possess the heritage and a matching surname). I foresee difficulty in pronunciation for average English speakers-- Ap-Pee-Ah? Negative. Ap-Fee-Ah? Strike two. Ahf-Fee-Ah? Yes, sir. "Apple" may appear in that list, on occasions. I think that the usage must be for extraordinary reason. Not simply because you favor the name.