My mother died 2 years ago.i never shed a tear, nor felt anything. no sadness, no nothing, just like anybody died. wasnt close but...splitting of ego?

Not exactly: I think isolation of affect would be the most appropriate term. You may wish to seek therapy if the issue still bothers you.

Grief: I see you suffer from chronic pain and fatigue, these can be signs of depression and i see you are on cymbalta, (duloxetine) i think you are grieving, in your own way. Try talking to a therapist about your feeling if you have not done so already.

Grieving: Everyone grieves differently. Just because tears are not shed, visible to the outside world, that internally there is no grieving going on. I would say find a reputable psychotherapist to speak with about what mom's life and death means to you. I would suggest either psychodynamic psychotherapy or psychoanalysis,