Well, I can't answer your question in relation to your fasting blood sugars, since fasting sugar levels and non-fasting ones have little in common...
BUT, 63 is on the low side to me, too! I honestly start experiencing symptoms of hypoglycemia when my BG falls under 80. I don't treat it until it's under 74, but I can tell...and the two times when I've almost passed out in public, my sugar level was only 65 and 62 - not far from where you are. Some people may not be so sensitive to low blood sugars, though.
I would say that you ARE experiencing hypoglycemic reactions and what your nurse said is incorrect. Did they give you any other information yet? Lots of women with PCOS are hypoglycemic, because we pump out extra insulin...it's definitely possible, but I hope it gets cleared up soon!
