a lot of professionals have a hard time believing in DID and the spectrum. dissociation in general like the depersonalization and derealization is more known/accepted, but even that is difficult for some professionals to grasp the concept of.

you could have had some trauma as a young child. even emotional neglect, etc. can cause a level of trauma and detachment which could cause a child to dissociate. not sure if you had emotional neglect or not. i had it in the way that my mom (single mother of four at one point) had to work to support our family, and when i wasn't at school, i was at a babysitter's. she also wasn't able to give me the emotional support i needed and neglected me in that way as i was highly anxious. she didn't mean to do that but did the best she could given the situation. i did have a lot of other traumas though early on, so that was just one type.

have you seen therapists that work with dissociative disorder clients? if not, they might be a better type to consult with. maybe you could find some to phone and ask questions before you decide if you want to see another one or not.