I guess you could be a sociopath, but it doesn't really sound like it to me. You could just be overthinking this due to being a bit out of touch with your deeper feelings. I was like that for years when I was seriously depressed - my emotions were numbed, and I thought something was wrong with me for not feeling things the way others seemed to. All my relationships were held internally at arms-length, but I didn't understand why. Like a glass wall between me and the world.

I don't know. When I cut people off it's very absolute for me as well. I don't have any doubts about letting them back into my life and no urges at all to stay in touch. It's just that in the quiet lonesome moments, when I have the courage to hold it, when there's no one else to be accountable to, I still feel the sadness. And sadness is just another face of love.