Hi. 2 things come to my mind. You've either been horribly damaged at some stage and putting up one hell of a defence shield, or you're a sociopath. I think, more likely the 1st, because you say you don't hurt people etc. I'm a little bit similar. People call me cold because I don't get attached to people & I hurt them when I honestly say I wouldn't care if I never saw them again. I know with me I'm not a sociopath, mine was severe childhood neglect & abuse. It's left me with this numb feeling & the thought that I'm just an actor, being everything to everybody.
Hope that helps. Good luck with it all. The fact you're posting on here must mean you care or want to change, maybe, so it might be a good idea to get a professional opinion.