Disclosing at work is a very personal choice and I would suggest weighing the pros and cons of it. I would also suggest that you wait until you're okay with the diagnosis prior to disclosing it (if you choose to do this). I have been open about my diagnosis at work and my personal life, but I agree it's not like letting people know that you have diabetes. The book in my signature has a good section on disclosing at work.

I found that educating myself on bipolar helped decrease the fear and anxiety I had about it. I hope you find this site supportive.