It's possible to have comorbidity with more than one mental illness. Some people with predispositions toward bipolar, autism, learning disorders, and other invisible disabilities have also experienced trauma in their childhoods, which can then lead to PTSD or post-traumatic symptoms or dissociation (which is thought to be related to either high stress or high trauma, typically prolonged traumatic experiences, but not always). Trauma-related disorders (PTSD, CTSD - not yet an official diagnosis, dissociative disorders) and anxiety disorders can go hand-in-hand. My T has said that there were a few veterans she had worked with who had both OCD and PTSD, like me.

A diagnosis of a dissociative disorder, since it remains controversial, would require a seasoned trauma-and-dissociation specialist (not just any mainstream psychologist) to diagnose. You can also try seeking out a psychiatrist, but they are even more skeptical about dissociative disorders, especially since many people with dissociative disorders don't react to psychotropic medications in a conventional way, which can baffle psychiatrists (whose jobs mainly comprise medicine, not talk therapy).