I can't feel sympathy for people
Why do you think you have trouble sympathizing with other people?
It's because I always ask for myself when sympathizing with anyone.
If you feel unable to have sympathy for others it could be because you are in your own head too much. Try making yourself happy first through healthy habits like eating right and exercising. Once your mind is right, you may be able to be more present and feel more sympathy.
I'm good, don't worry about me.
Do you have empathy? Sometimes we don't have sympathy for other because in our opinion they don't deserve it but empathy is important to have because it makes us human.