Hi and welcome to beyond blue. just to add a little to what Sophie_M replied....
I don't know if this relates to you but a little story about me - I would work from for too many years. The effects of this were social isolation, loneliness that would lead to depression etc. So what Sophie_M said above happened to me. That is one part of it. I now work in an office space. I still have a sense of emotional detachment and things which I feel I should have some sort of emotional reaction to .... well, I don't!
So the question is... am I emotionally numb? Listening to song for the first time might evoke a lump in my throat and that is because I connect with that song. Listen to it two more times there will be no reaction. Movies and books don't get me excited. Regarding the death of friend, I was business-like. I spoke about this with my psych ... it could be age related, medication related, experiences etc. Very hard to say.
Perhaps you could give an example of situations in which you feel this way.
If you want to chat some more I am around.