I think you will find yourself in good company....!
I think it would probably benefit you to take a refresher course..most of the community colleges offer them...the one here in my city lasts 8 weeks. I have a friend who just finished it-for reasons similar to yours and she loved it. She is now happily back to work after 5 years....
I don't think you should divulge anything about your bipolar to any potential employer...or any actual employer for that matter...it is not relevent to any interview process..as long as you are medicated and well controlled, it is none of their business. It is confidential. If you are asked why you haven't been working..it's because you have been a stay at home mom...not because you have bipolar disease. That doesn't have to be mentioned. The odds of someone hiring you are just as good as anyone else getting hired!
SO come one out...It's time