I have to agree with MDDBPDPTSD, it sounds like what you're experiencing is connected to your BPD thinking. I think it's something many of us experience so you aren't alone or strange With BPD, we often focus on someone new as wonderful and perfect and then a bit later, when they do something we might not agree with or reject or hurt us in some way (which is normal in human relationships), we split them to being bad. It's because we often have difficulty holding both bad and good qualities together at one time. I know that I'm able to "intellectually" know that everyone has both positive and negative traits, but when it comes to my own personal relationships, I seem to hold the person(s) I'm involved with to a higher standard, and I tend to insist that they occupy the pedestal position. If the person makes a mistake, I shift him/her into the all bad position and simply walk away or lose interest. In a sense, I dismiss them; not in an angry or negative way. I just walk away. Understandably, it makes for difficult personal relationships. Hope you're able to figure things out.