I act emotionless in certain cases

I am kind of a sensitive person, who can correctly guess slightest changes in the environment or in human behaviors and act accordingly, but on some ocassions act like emotionless or kind of maybe beat up my emotions so they won't show up, eg, when my dear ones died, i hardly wept or shed a tear, instead i feel kind of empty but in the mean time, the sadness clings to me like a tap water, but still i dont show emotions or feel the intensity, so i hardly get shocked on certain news and events.