I have DID but I don't really start remembering things until around High School age. It is my understanding that DID has to start with trauma from a very young age. I'm sure there are other kinds of dissociation though that might cause your memory lapses from later years. Have you ever ask your therapist why they think you have the memory gaps if there's other reasons besides DID maybe they can help you with that. I'm sure there are many reasons for people to have blocked out traumatic memories.