something i learned years ago from a pdoc i was seeing is that some therapists, pdocs, psychologists, withhold diagnoses, or labels, because in giving what a person has a definite identification, it can cause more problems than it can cure. i think its called a self-fulfilling prophecy: the idea that if you believe you are something, you become it, because you believe its what you already are. i hope i'm explaining this better than i think i am because i dont want to confuse you. the point is that sometimes if we know exactly what our problems are we can learn more about how to approach them. but at the same time if we think we're fated to something, maybe we'll start making excuses for our behavior, or adapting new behaviors that fit the diagnoses.
if you feel its an important part of your treatment and healing process to know what they think is wrong with you, by all means, speak up. i think youre entitled to that much. and playing an active role in your therapy is very important. my friend rachel always says shes her own medical advocate. she always makes sure that she has input on her treatments. maintaining control can be very comforting. especially when life is so darn unpredictable.
i dont know if any of this helps, but i wish you best of luck in your therapy, and am sending big hugs your way.