For most of my life--I'm 20, so not that long!--I've felt pretty much numb. Like I don't feel emotions to the intensity that other people do. I used to practice facial expressions, and whenever I laugh, it's forced because I react to other people's reactions. Which kind of sucks because now it's a subconscious hair-trigger reaction, where if I see someone's face LOOK like they're about to laugh, I smile or snort. I wouldn't have ever made a post about this, but recently my mother was hit by a car. I heard the accident, went outside where she was there with my dad. She was lying on the ground, bleeding and unconscious. A truck had lost control and skidded off the road, hitting her and one of the cars in our driveway. It looked like she was dead, and my dad was hysterical. But I was really...I don't know. I didn't really feel anything. At the time, it really helped because I was my dad's 'rock', so he says. I made him stay calm, as well as the driver of the car. But it was only after the incident that I felt like maybe that behavior was a little concerning? I've been in a car accident before that completely totaled my car and didn't feel much. I got back in a car the next day without any issues, even though my family was concerned that I could have PTSD, or something.
It's also started to affect my relationships with my siblings. Whenever they come home with a problem, or show their emotions, I get annoyed. And I figured out why. I get frustrated that they don't just stop feeling whatever they are feeling. Like how I do it. And I subconsciously got angry, would yell at them occasionally, when they couldn't.
As for friends, I don't really have many. I have never had a 'best friend'. That's too much commitment, which is exhausting. What I do is make very shallow friendships, where everyone in the group knows me, I am included in their conversations, their group projects or whatever, but I usually can leave class without anyone tagging along.

Any advice would be a great help! I've been pretending for a really long time, but I think it is important for me to acknowledge these issues. Thanks.