I was upset too. I hugged my wife. Kissed my baby girl. Mourned for the children and teachers. I was sad about the lack of mental health resources and angry about the guns.
The more I thought about guns the more upset I became. I laid awake for hours on Saturday night in sadness and anger. I found myself contemplating my own gun experiences - mostly just shooting guns as a kid. I decided that I want fewer guns in my family's future. Then I thought about one person that I know who has a gun, someone I trust and who trusts me. I decided I would call him up and ask him to consider destroying his gun. This idea didn't help me to sleep.
It wasn't easy. My voice was shaky. I did not manage to coolly and clearly explain the data that describes why guns in homes are dangerous. I did not win a debate but the conversation didn't devolve into abstract politics. I wish that I was more sensitive ("having a gun to defend yourself is a stupid idea") but conversations in the real world are like that. I'm not sure if I will succeed, but I'm trying to care for people I love and make the world a better place one relationship, and one gun fewer, at a time.