Hello, and welcome to Allnurses! I'm a fellow BP'er and can relate to so much of what you've posted. As you get to know people here, you'll find that there are many, many nurses with mood disorders and other mental health diagnoses who are working every day, making a life and building successful careers. You can do whatever you want, stigma or no stigma!
However......we are a nursing message board and cannot offer any sort of medical advice per the Terms of Service of our site. I'm glad you plan to speak with your pdoc about your anxiety issues; he is really the best person to advise you, as he knows you and your condition better than strangers on the Internet. You also may want to think long and hard about taking the ER position, as the adrenalin runs high and frankly, unless you spend most of your time being hypomanic (and most of us BP 2's tend to do exactly the opposite) the job may cause more anxiety than you can medicate. BTDT, almost got myself hospitalized for it.....and mine was only a med/surg job.
Anxiety is such a common co-morbidity that I'm almost surprised that it's not one of the criteria for a diagnosis of bipolar disorder! It can be absolutely crippling, and yet it's rarely taken seriously. People often say things like "Breathe...." or "snap out of it, willya?!" and they just don't know that it doesn't work that way. I wish you the best in your career decisions and encourage you to share your experiences with the membership here; even in the nursing world, mental health is often poorly understood, and it takes nurses like you to educate and inform others that one can live with psychiatric issues and still be a great nurse.