The short answer to your question is yes, as far as I’m aware having two or more concurrent diagnoses is possible even common. The DSM is a very controversial text in many circles and the vagueness of dealing with the human mind makes it often hard to fit people in one nice neat diagnostic box. That said it sounds like you have had a lot of diagnostic labels thrown your way. I am not a doctor of therapist so I can’t say what’s right or what’s wrong just that I can see how that would be frustrating.