18 y/o male

I don't really know how to describe everything but here it goes

• I am not able to empathize with others. This includes acquaintances, close friends, and family members. If an acquaintance tells me about a troubling time I will pretend to feel for them when really I don't care. With a family member or close friend I usually will joke about their situation with them because I feel like it lightens the mood (I don't enjoy people telling me their sob stories because I have trouble reacting properly so I respond with jokes). Overall I just can't emphasize or feel bad for people unless it affects me personally.

• My mood also changes rapidly. I can go from being depressed to extremely happy in a matter of minutes. Same with every other emotion other than anger because when I get angry I can hold a grudge for days.

• I haven't cried in over 3 years. Sometimes if something bad happens I will find myself on the verge, then poof, the sadness is gone and I carry on. I've noticed that I react very differently to traumatic events than most people. For example when my family pet suddenly died, my whole family was grieving while I felt nothing ( I had it the worst because I found the body). I did though, pretend to be sad in order to miss school the next day.

I've been super confused by my behavior and need suggestions on what could be wrong with me. Thanks.