I'm not sure about
the diagnosing capabilities of a PA. I know they are supervised by physicians, so I'm not sure if she would have to run the diagnosis of a chronic illness by the rheumy or not.
In my opinion, one of the most helpful things to take to your doctor when describing your pain is a pain journal. You can use a notebook and make your own, or use something like this:static1.1.sqspcdn.com/static/f/780996/10986694/1298931690137/Partners+Againts+Pain+Daily_Pain_Diary.pdf?token=ys4QSg%2BiJCcdUDhU2oWM9AqRtSE%3D
If the PA can't diagnose, maybe she could forward it to the rheumy. But if you aren't satisfied with him, maybe it's time to find a new one if you can. It's so hard to work with a doctor that you don't feel is compatible with you.