New to this, please help

I started seeing a new therapist about a month ago and she believes I have DID. About four years ago I was diagnosed with Borderline Personality and I had accepted that diagnosis. She says I probably don't have BPD, just that there is a lot of overlap and most psychiatrists won't diagnose as DID.

All my life I've had voices inside my head that argue with each other or comment on my life. I say all my life, but I don't actually remember a lot of it. I have large sections of autobiographical amnesia. What I do remember is mostly negative. In first grade I became afraid of bathrooms and started peeing myself in class and the shame led to my first experiences of dissociation. In fourth grade I had a teacher who was emotionally abusive. She'd single me out for mockery in front of my classmates and made me burst into tears in front of everyone almost daily. She separated me from the rest of the class by moving my desk to the back, keeping me in during recess, forcing me to do homework alone during any fun activity like music/art/field trips/gym/etc. I frequently lost time during this period of my life and have only a few memories from it.

Almost immediately after this my family moved across the country and my parents started fighting, eventually got a divorce. Few memories of this time other than my mother crying often and one big fight in the middle of the night that woke up me and my little sister. My dad effectively disappeared and my mom wasn't really around emotionally to help help deal with this. This is when most of my long-lasting issues started; daily panic attacks, insomnia, hitting myself, phobias of chemicals and bad food. In early high school I started self-harming and starving myself and dealing with bouts of extreme anger which made me feel ashamed. I was hospitalized and attempted suicide after I was released. After that failed I had better control of myself.

Sorry for the wall of text. I'm just feeling kind of lost here. I always acted really rudely to my internal voices, ignoring them or trying to make them leave me alone. In therapy, I've been talking to them and they've been answering and I don't know if it's real or just my imagination playing along. I didn't think what happened to me was severe enough to cause multiplicity. The voices are starting to differentiate themselves and give me names and when they appeared. I'm just kind of freaked out. Any advice?