I have known people like this and have conversations with myself, I am certain I am at least bi-polar but have not bothered to have a doctor medically affirm this as it has become obvious too me. I understand it can be hard to feel like we're different but know that you are beautiful no matter what people tell you and if you do your best you can still be anything ou wanna be. At times people like this can feel hopeless. Hopelessness is not as bad as it seems though. In fact it is a gift to those who feel it often enough, you will realize that when you have nothing to look forward to their is nothing stopping you. These are some words from 'Fight Club" that have helped me: "It's only after we've lost everything, that we are free to do anything." -Tyler Durden
Don't be upset at the term, "borderline personality disorder" is a stupid label, and it is only a clinical term. The Doctors use it to try and save time by labeling certain personality traits. Do not take it to heart - I had that diagnosis and it hurt me for a long time. Your personality is fine - not disordered. I was there, I know how it feels.
My brother was diagnosed with BPD. I remember him being very sullen, angry and narcissistic. He also felt no remorse after some pretty bad things. This may not be you at all, but that's the experience I had. Google it for more info!