This subject just came up in the Unmoderated section. I put my experience in there.
I'm sure there's somebody here better able to talk about the whole thing of losing time and not remembering. I was always able to watch myself from far away doing things. I also think the diagnoses of Multiple Personality Disorder (now called Dissociative Identity Disorder) is a dangerous one. If a person doesn't have parts, but has a therapist that believes there are parts, it can really mess you up.
But I hear you about having people tell you about things you don't remember at all. I went through two very dissociative phases--one in my teen years, of which I remember very little about, and the 5 years I spent crashing from my past. My wife was telling me about some big thing I was involved in during that 5 year period where some person griped to my church that I wouldn't speak to her and me having to defend myself or something--complete blank. She might as well have been telling me about her uncle Leroy because as far as what I remember, none of that happened, but I believe her. I mean, she was there, even if I obviously wasn't.
In the "fight or flight" world, I was flight. I remember the parts taking over and I could not stay one more millisecond wherever I was. I'd get out of moving cars, walk to the middle of nowhere. But I also remember those feelings when I was a kid. Hiding up in the forest and hearing my family calling me. I got to where I hated the sound of my own name. I wanted to disappear. To make them quit calling me, because I didn't want to be in that house with those people.
When we begin dealing with our pasts, there is so much emotion and so much pressure to release that sometimes it leaks out. And it can be scary. Having read your story, you must have more stored in there than I can possibly imagine. It's no wonder it's screaming to come out. I know it's scary, but it does get less powerful. Writing here and letting the rage come out in safe places is the key to lessening the pressure. After a while there's not so much to hold back. It's all out where it can be validated by people you trust.
Splitting is a good name. Remember that if there was splitting, it happened when the horrors were done to you by people you should have been able to trust. Now we can begin to let the splits heal and eventually gain a little peace.
I hope this helps. Sometimes I get to writing about everything and I can't stop. I'm sure others have better insights into what you're having to deal with. But I feel for you. Hang in there, OK?