Ami,
Yes, I am perfectly fine with talking about it here on the board. My reality is what it is, and damn the torpedoes.
Since you don't seem to have any of the usual signs of being multiple, you likely are not. MPD is one end of a spectrum of dissociative disorders. Post-traumatic stress disorder (PTSD or Shell Shock, depending on your generation) is a similar disorder. Fugue states, when you sometimes hear about a person completely forgetting who he is and starting his life over, are another form of extreme dissociation.
Dissociation is psycho-lingo for that state in which you are not completely in touch with the world outside your own head. It is a normal phenomenon on one end of the spectrum. For example, if you are so involved in a book that you do not hear someone calling your name, that is a normal state of dissociation. It is related to the ability to focus on one thing to the exclusion of others.
In between the extreme ends of the spectrum, are states like you describe. I am sure they have a name, but I don't know what it is. When I went to Incest Survivors Anonymous, I met a lot of people who felt as you do, very fragmented. I think this is a way we survive the horror-houses of our childhoods. As little children, we need our parents. We need to believe that they are wonderful people who will always care for us. We need to believe in their innate goodness, so we can feel safe. So in our child minds, when they act badly to us, we believe we are the cause of it. After all, if they are the perfectly good people we need to believe in, the only reason they would be bad to us is that we are bad. This kind of black-and-white thinking is normal in a certain phase of childhood, and if we do not have an opportunity to grow past it and learn to see the world in shades of gray, then it sticks. Abusers like to encourage this, for obvious reasons.
It seems to me like you learned one set of survival skills that helped you get along by being really nice to everyone and getting approval (Whitie) and another set of skills that you could pull out when you needed to be more assertive or just had had enough of being a doormat. (Blackie) Of course abusers don't like it when you stand up for yourself, so Blackie got labeled BAD by them, and as a kid you accepted that.
I forgot what I was trying to say. I am about to go to bed now and the computer is trying to restart itself, so I will post this much for now and add to it later.