Borderline Personality Disorder Exchange

So, I was diagnosed with BPD in July 2012. I have a feeling my father has it as well and it was passed down to me because I have always been extremely emotional and sensitive. My father refuses to believe anything is wrong with him...and his mother (my grandmother who died before I was born) was constantly in and out of the psych ward. My parents divorced when I was 12 years old and I am now 21 and living in my mother's basement with my step-father and my older brother.

This past New Years Eve I went to a party with a bunch of friend (all good friends who aren't doing drugs or anything). My mom knew about it and I had told her I wasn't gonna be home cuz Tony's (one of my friends) mom said no one was allowed to leave since we were drinking. Smart mom right? Well, I had too much to drink but I was safe and all and nothing terrible happened but I was pretty hung over the next day. I was suppose to go see extended family to exchange gifts but I wasn't up to it and thought it would be inappropriate since that side of my family are all grounded Christians and would see me as some kind of alcoholic. I texted my mom and told her I was hung over (thought being honest would be the best way to go) and that I wasn't gonna be able to be home in time.

I decided to spend the rest of the day with my bf of whom I had asked out on New Years. He had liked me for 2 years and I finally gave him to ok. We hung out all day till about 9:30 when my mom called fuming mad cuz I didn't tell her when I was gonna be home. So I headed home then and when I got home I was ambushed by my family who told me what and irresponsible child I was for not keeping my promise to see my family and not telling them when I'd be home. I lost my temper and threw a chair at my mother (which is something I have NEVER done in my life because I have never been an angry person until about year ago). I was told I was an alcoholic for drinking on New Years Eve and that I was probably doing drugs (which i haven't done in a long time) and all that kind of crap. My mother claims she sent me a text asking when I would be home but I never got it. My phone was taken away and they now complain about communication issues and crap.

Bottom line is that I did was I thought was right and smart and next time I know not to promise anything to those people. I do nothing right in my parents eyes...I have come a long way from where I used to be and no one ever tells me that they're proud or anything. I'd like to know your thought on my situation. thanks for taking the time to read.