What is Borderline Personality Disorder?? What is this Baker Act?

I suffered a Heart Attack on Feb 14th of this year.. I have been depressed ever since.. My husband and I went to a hospital in Florida ( Just moved to Florida) he told them I was having chest pains and had been depressed and spoke that maybe they would be better off without me cause I felt useless.. The Baker acted me and put me in a nut hut for 72 hours for observation... Since we did not have insurance yet in Florida they put me in a state run hospital and the conditions were terrible and most patients there were homeless or drug addicts. I was very difficult and angry for being there.. When I left the psychiatrist attached a diagnosis of boderline personality disorder to me..Reading it it sounds nothing like me maybe when I was like a teen-eager I am now 47 years old.. I feel like she put this label on me simply cause I was angry because the nurses were not giving me my cardiac meds and I was angry for being there. What the hell is this Baker act and how in the heck did she diagnosis me in 72 hours with a major personality disorder!! If I had been a man and angry would they have labeled me with this.. Oh my gosh I am so pissed and upset!!