Ok I'm going to jump in with both feet here - hope I don't drown...
I think that those of us with serious and debilitating emotional issues sometmes react harshly and without thinking - it's the nature of the beast. However, I think that sometimes we are unconsiously trying to push people away, to make them dislike us and retreat from us. This validates our feelings of being unloved and unwanted. We conveniently skip over our little melt-downs and blow-ups and just rationalize to ourselves, "see, they really DON'T like me or care about me." I know I've done this in my life but I never realize it at the time, it's only later that I can "see the forest for the trees". I also think that a lot of us, myself especially, attack the ones we love, the ones closest to us, perhaps just because they are there, or maybe just because we believe that they love us enough to forgive us, whereas strangers might not be so kind and understanding. For me it works best if (when) I realize I've behaved like an ass, I apologize sincerely and forgive myself - which is often difficult as I'm harder on myself than anyone else could be.
William Blake said it very well: "And throughout all eternity, I forgive you, you forgive me."
Just my opinion...
least