Goodness! That's a lot to go through all at once!! I have POTS myself along with supraventricular tachycardia (though that seems to be more under control after three ablations.) I take Toprol xl too and feel a lot better with it. Teri's questions to ask are good ones. I can't think of any myself right now...it's just after 5am and my brain is still asleep.
My suggestion for you is to buy a notebook. I have a five subject one divided up for my regular doc, my cardiologist, pulmonologist, hospital visits, and tests. Each time I see any of my docs, I write the date, time, and doc at the top of the page. Underneath, I write why I'm going to see him...new symptoms, follow-up, test results, etc. Then I write all my questions skipping lines so I can write the answers down. I also let my doc know that I have questions to ask him before my appt is over. Also, when I leave (usually before I pull out of the parking lot) I write down what happened at the visit. I make a list of any new meds he gave me and reactions...also any tests he wants and why. Sometimes I do all that while he's telling it to me in his office and then I read it back to him to make sure I have it right.
I also carry a folder with me to put any paperwork I get from my docs. They will often give me information sheets and pamplets on my conditions.
Oh wait...I just thought of a question...it's about POTS. Has anyone told you to wear compression stockings? They keep the blood from pooling in your legs...makes standing up a lot easier!!! They're not the most glamourous things...I'm 27 and wearing tight white hose is really not my thing...but they do help!
I hope this helps. Keep us informed!