Talk to your therapist. Most have a short list of psychiatrists that they have a working relationship with & can compare notes / saving you both a lot of time & money.
If they don't... Then you're looking for a psychiatrist, ideally.... Although a neurologist or prescribing psychiatric nurse would be the next best options. Avoid general practitioners. This is your brain. You want a brain expert. Which either means psychiatry or neurology. The keywords to use when looking for a practitioner are "Medication Management".
Except for possibly the first apt., they tend to be short, about 5-15min or so, so don't freak out at $400-$800 per hour published rates ;). Med management appointments generally cost the same as therapy (around $100), but you only go in once a month or once every three months once you've found a good med regimen. So you're not looking at doubling your therapy bill to see a prescribing physician!