I didn't know where to put this so I thought this forum was the best one:

I'm always seen as a very emotional person, I get happy and sad easily over the smallest things, like not having time to go out or have quality time with my bf, or a customer at my job yelled at me, things like that. But when it comes to things I should really be sad about, I don't feel anything:
•My parents used to fight a lot, and I remember one time when I was about 15 years old (I'm 20 now), my dad came into the room and told us that he was going to leave, that he was no longer going to live with us. My sister cried, and I just sat there like "okay then, bye". I didn't really care that he was leaving when I really should have. He stayed because my sister got mad and started telling him things.
•When my dad actually left 2 years later, my mom and sister were sad about it, and I did cry a little bit, but I got over it extremely quickly. Quicker than everyone else.
•That same year (almost 3 years ago), I lost a really close friend of mine because of me: he had told me that one of his family members had passed away right in front of his face, and what did I do? Nothing. I've never had a family member pass away, except for an uncle of mine but I was very young, I don't remember him. I didn't know what to tell my friend, I didn't know how to be supportive, and it took me almost 3 years to come to terms with the fact that I didn't care at the time. I had my own personal problems to worry about, and I thought his trauma wasn't a big deal, when it really was. He needed me, and I wasn't there.
•When my parents decided to separate a little over a year ago, I didn't feel anything. And when my mom found someone else, I didn't feel anything. My sister, however, was sad/mad about the whole situation.
•It wasn't until today, when I found out a couple of hours ago that my sister has been harming herself, when I realized something is wrong with me: I don't feel anything. My mom and dad are devastated, even my boyfriend is hurt about all this, and I talk about it like it's nothing. I don't cry, I'm not mad, I'm not sad, it almost feels as if all these things haven't been happening to me. I went to work like nothing. I completely forgot about it.

If you've reached this point, thank you for reading this. It means a lot. I just don't seem to understand why I make it seem like I don't care about things that I should really care about. I do have emotions, I do have feelings. I express myself to people, but it's just these major things when my body just shuts down and decides that it's not a big deal, and it worries me a lot.