My wife's got the same "key deafness" problem. She has incredible trouble singing harmonies - basically she has to stop listening to everyone else in order to do it, because of the level of concentration she needs, and that can be a problem at times. She's also unable to take a key from a chord on a guitar, and doesn't seem very confident with doing it on a piano either. But she can hear and sing back individual notes perfectly well, and she's got one of the best jazz voices I've heard.
Of course, a standard problem is that how you sound to yourself is not how other people hear you, a fact which anyone who's recorded themselves will know all too well! The bone conduction through the skull seems to carry more bass than actually gets out into the room. Me, I reckon that if I'm sounding almost like Elvis to myself, then I'm probably far enough out of my whiny breathy voice to be acceptable to everyone else.
Daylia, perfect pitch is apparently close to a standard ability in China and some other far-East countries where different pitches of voice give different meanings to words. What I heard, you mostly lose that ability at age 2-3 when you learn to talk properly - your brain starts with the ability to do anything, but when it starts learning a language, it blocks off all the other ways in which meaning can be communicated.