I found myself in an eight year abusive relationship where my partner was either trying to hurt me or herself. The last couple of years i felt exactly as you described, I had literally given up. The strange thing is that I functioned pretty well and no one knew which just made it feel even more pointless. I'd love to tell you that it just ends one day but it was hard work and traumatic trying to change my life and although I'm much better and have recently married someone else I still get bouts of feeling like that. The big thing that I have taken from it is that I think it was a defence mechanism because the fact that I cared about my girlfriend was the reason I stayed with her - so I stopped caring. I hope you can take something from my experience, I'm often told to connect more with people, when I am, I try to.