Personality Disorders Support Group
Personality disorders form a class of mental disorders that are characterized by long-lasting rigid patterns of thought and behaviour. Personality disorders are seen by the American Psychiatric Association as an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the culture of the individual who exhibits it.
I am guessing here but I don't know if therapists use this diagnosis so often. I have never heard of it and I read about diagnoses somewhat. I used to be so clingy...my husband is....and we never got this from a therapist or doctor (not because we don't show signs).
Maybe try to reach out to people with the trait of being clingy as opposed to a person with the diagnosis.