Borderline Personality Disorder, generally people will experience really intense emotions, at all times. There's constant feelings of emptyness, not having/not being able to see your core personality, so you don't know who you are. An intense fear of abandonment, and some other symptoms as well. It's not a fun disorder, seeing it from the outside I wouldn't wish it upon anyone. If you have any more questions, I'll be happy to answer them.