How do i get my Best friend back?

okay.. so a while back me and my best friend had a bit of an argument on facebook, about things that are happening in my life and in her life, and how she thinks i have changed a lot and how its all negative.. and i will completely admit that in the past i had done and said things that I regret so much looking back on things, and i told her that, and that i was trying to change and become a better person.. and i still am.. about a month ago, i had a mental break down and tried to overdose.. i went to emerge, and a couple weeks later i got diagnosed with Borderline Personality disorder, which kinda explains a lot of the things that have gone on between me and my friend, but the thing is she doesn't know anything about it and i don't want to make it seem like im blaming everything i did and said on that. she was my best friend in the world... and i don't know what to do with out her.. can anyone help me figure out how i should get her back??