I can understand why you might feel confused and angry about the differing diagnosis.

Are you assuming the psychiatrist is right and the therapist is wrong? Could it be the other way around?

I don't feel it is uncommon for two different MH professionals to disagree about a diagnosis.

I also don't feel it is uncommon for a psychiatrist to diagnose a person with a condition for which they can prescribe medication. That's what psychiatrists know how to do- prescribe medication.

Yes, talk to your therapist. I'm not certain I would be confrontive. Maybe I would treat it more like information gathering. But you decide.