I’m Insensible

When I was younger I was a very caring person. When a person of my family or a close friend of mine did not answer the telephone or was not at some place on time, I started to think that a very bad thing happened like he/she was kidnapped, killed or had an accident. Then, a person who I really liked died. A few months later (I don’t know if it’s related) I realized that I started to not care about people I’m close to. I was always close to my grandparents. My mum’s father (my grandfather) died a few months ago and I didn’t get sad. A few days ago my dad’s father (my other grandfather) died too and I didn’t get sad either. I mean, I was shaken by at the moment but then I didn’t think about that anymore. Today my mum asked: ‘Do you miss your grandfathers?’ ‘Why?’ ‘Because I didn’t see you cry because of their death.’ I didn’t know (and I still don’t) what answer to that. What should I do? I’m felling very insensible. Does that happen to you too? Please, tell me.