Emotional Meltdown

I am not talking about me, it's about my son, Izz. He will be 4 years old this coming February. He is intelligent and thinks through EVERYTHING. We also call him cautious. But during the past few days I realize that he is becoming emotionally sensitive. It's not the tantrums or behavioral problems I am dealing with, but I think he is so sensitive.

For example,
1. One day during Sunday after hubby had a week holiday and that Sunday hubby had to go back to work, when he woke up he asked me,
    Izz: Mama, where's papa?
    Me: Papa is in the office.
    Izz: I'm sorry, mama. It's ok papa will come back soon. (consoling me)
    Me: (Uish, apesal tiba2 sensitive and sorry kat I? Nak tergelak pun ada)

2. I played "Cloudy With a Chance of Meatballs" and sitting besides him. I was playing cooking dash on my iPhone, then I saw he dissolves his tears when the part Flint Lockwood ruins everything during the opening ceremony with his invention. (macam kesian and sedih for Flint anak saya sampai menangis okeh) Itu belum tengok cerita Hindustan.

3. This part really hit me when I saw him crying alone in the room. I remember before that I put socks on his foot and he told me he wanted to take it out and I told him it's really cold right now, u better put it on, I'm not yelling or what..just being stern.... Then he went to the room, bila I cari dia tgk dia menangis teresak esak okeh..sampai basah bantal with his tears.

I'm quite worry coz it seems like he cries if I look at him the wrong way.  Neither his papa nor I ever yell, hit, or use mean language. We use time outs for discipline and do A LOT of talking and reassurring.

Is this normal?  Is anyone else dealing with this?