Why did you decide to see the psychologists in the first place?

Due to my most wonderful disorder, my sense of self is nearly non-existent. Much like you described, I can easily try on a mask and it will seem real. Personally, I rather enjoy this "symptom" of my disorder, as it's been quite useful in the past. But I understand how it can be unnerving at times.

The sense of self usually develops in the late teens or early twenties, so it's likely yours still will develop eventually. I don't know a lot about developmental psychology, but, from what I've read on the subject, people who were encouraged to experiment with these roles (or masks) early in life tend to develop a stronger sense of self. So it's probably a good thing that you do try on these masks. I would advise, however, that you avoid trying on the "mentally ill" masks and focus more on roles that will lead to you being socially and financially successful. Just a suggestion...

If your sense of self doesn't develop, enjoy the fact that you don't have to be tied down to one self-identity. And become an actor.