I just cut off, and out, my "best friend" of a few years. 
Well, he was actually my ex of one year who forced his way into my life for far longer then he should have stayed.
He constantly fought with me, made my SO uncomfortable, made unwanted advances despite my protest and generally made me feel like shit.
So, I did it. I got rid of the poisonous element and took control of who can and can't hurt me. 
Now though, I feel as though I've done the right thing but still somehow am the bad guy; as though I have betrayed someone and am a terrible friend to anyone. 
Does anyone else empathize, or have advice? I could really benefit from someone with my sort of brain patterns to chime in. 

(EDIT: This person also has Narcissistic Personality Disorder. Am I the only one who sometimes feels like a magnet for others with uncooperative brains? It isn't always a bad thing, such as in the case of my bipolar big sister.)