I agree with the others that have suggested writing things down if that's easier for you. it also helps so that you don't forget anything during the appointment. In your first appointment there are usually lots of questions and it can be a bit difficult cos they can ask hard questions. Make sure that they are aware of how anxious the situation makes you cos they may want to treat that before they dig to deep into things that might be upsetting to you.

Another option may be to get your family doctor to prescribe something for the anxiety when you go to get the referral for the psychiatrist (pdoc) if you feel that the anxiety of actually going to see the pdoc would be overwhelming. Normally they would probably prefer for you to wait to see the pdoc to get meds though.

I also think that it doesn't sound like BP but I'm not a doctor so don't take my word for it! Good luck finding a diagnosis and more importantly getting some relief from your suffering.