((Trace)),
This is because when you were exposed to death it was unexpected and traumatic. You also suffer from PTSD and the area of the brain that struggles a lot is the amygdala which is the part of the brain that carries our emotional responses. Trauma reduces the effectiveness of the hypocampus and the hypocampus is the part of our brain that filters things out so experiences are filtered "before" they reach the amygdala. This is why those who experience a major trauma where it results in PTSD taking place will say, "why can't I just like I used to".

When you were young you witnessed a sudden and traumatic death in your family. That affected you and you also saw how badly it affected the adults that were present at the time too. A sudden and traumatic loss can not only affect a person's hypocampus, but because the hypocampus often literally shrinks when experiencing a major trauma, just recalling that trauma can be hard simply because the amygdala is now a lot more sensitive because the filter one used to have isn't working as well. The individual has to learn new ways to gradually gain new filtering skills, and sometime the hypocampus, which it can take time does heal some.

We are slowly gaining in our understanding of how our brains can be affected when a major traumatic event takes place because we have created new technology that allows us to see more of the brain and how our brains actually work.