It's often trial and error as to what medications will work best for us, but a psychiatrist is more knowledgable when it comes to these types of medications. What you experienced is very common and I'm glad you're back on track. Best wishes.
Unfortunately, sometimes our primary care docs are not that used to prescribing some of these medications in my opinion, but they are still doctors of course:). I am glad that you went to see a new psych and are back on the right track. I have switched before and my new psych changed it once I saw him as well.