Is your employer aware you have Bipolar? If so I would certainly give them the letter .. If not .. well then you are probably going to be asked some questions... Yes Hippa laws are there for a reason , for privacy.. But most letterhead from a Doctor will state there speciality, so proverbial cat will pounce outta that bag, maybe not for specific diagnosis , but it will show a MI is there..

It's apparent your starting to unravel.. You need to do what you need to do so that you can avoid needing IP and just taking care of yourself so you don't wind up dealing with physical problems on top of managing your BP problems.

Take care of yourself