You know, I've been thinking about this a lot since reading your question. I honestly think it takes time, validation of your experience by another - preferably a therapist who understands -, and a lot of work learning about your various parts and starting to communicate with them. Are you working with a therapist?I was about to start a thread about this and found yours.
I haven't a diagnosis but parts take over and I dissociate(hanging out with parts) several hours a day. Still I talk to myself in the same way like you do, I make it up etc.
How do I break out of the denial?