I think your doc has a good idea, may even save time and money, trying not to concentrate on if it's either or, at this point, it's not like it's new, you said you had tried other meds for years. Not knowingly, many years, and time lost, for me was due to my Internest/GP treating me for "clinical depression" which didn't do the trick, after all the years a therapist detected the true DX and referred me to a pdoc for proper meds and treatment for mild Bipolar, it worked.
Okay not everyday is a walk through "Mr. Roger's neighborhood," but life happens, and I can handle things in a better way compared to the non DXed version, years ago.
Lots of luck, and always feel free to come here, update us, or just a little old "chit chat".
Take care,
DE
I'd say give it a try, the doc has a good point