It sounds as if you are talking about DID-disociative identity disorder, once called multiple personality.

I was ten when my father died-he was only 37 and went to work one day and we never saw him again. They told me that they had to drag me away from his coffin for three days. After that, I was not consious for most of the next three years. I was abused for eight years altogether and when it was the worst, something stronger came out of me and kept me from remembering.

I believe black outs are associated more with drugs and alcohol-in DID, there is always a part of you that is awake and in charge. You might want to check out the DID section.

Best of luck