From what I've noticed, BPD makes me feel either intense pity or hatred towards a person. Nothing else. 

The most intense feeling I have is towards my partner, who cares about me even with my abnormal and destructive behavior. I insulted him for no reason because he annoyed me with everything he did, then threatened him with suicide when he wanted to leave. Sometimes a deep sense of pity hits me when I think about how much I have to endure in this relationship - it's like I "wake up" from that state of feeling only hate and return to the empathic state. That's not regret (unfortunately), it's just pity and it's a terrible feeling. 

The same thing happens to my mother, my sister, even my dog. Every time I see them a little upset or know they have a problem, I feel so sorry I want to scream. Sometimes there's no particular reason for feeling that way, my brain is just convinced that I should pity them without giving any explanation. However, that doesn't stop me from feeling intense hatred towards my mother and sister when they happen to cause me the slightest inconvenience. 

Can someone relate? I don't even know how to better describe this behavior.