it's been 9 years

Today I was having a conversation with my teacher which ultimately led up to me saying "he was killed" when he asked what happened. My chin was quivering and my eyes were watering and I was trying as hard as I could not to cry.

It's just it's been 9 years and even if I think about it I start to cry. Most of my friends don't even know how my dad died.

Something in one of my classes yesterday that we read  reminded me so much of my situation I left the room and started to hyperventilate and just bawled.

Which is why I told my teacher today I couldn't participate and he asked me why.

I just don't know what to do. I constantly just feel this dreadful sadness.