I'm a senior Psych Major. The first time I ever saw BPD explained to me, I knew. It was an outline for my life as long as I can remember. I've read many books on it as well, and I know I have BPD. There's not an ounce of doubt in my mind.
I know what you mean by just not being able to see shades of grey. If someone does something bad, people will say "oh well I did this good thing for you too remember?"
All I can think is that why does doing something nice some other time excuse you for doing what you just did? I don't get it at all.
My husband and I talk about it all the time, but when we get in arguments it seems that every discussion and rational thought is out the window.
I know I need help for this, but I don't know where to start. Also, I'm afraid that if I bring up my psychological issues to my doctor I wont pass the psych eval to get my gastric bypass, which is the most important thing to me (and I know what I'm getting myself into) to be able to live my life. I'm at a loss for what to do