"Write to heal. Because it is your right to heal."
That is powerful and meaningful.
I just read your post about the shooting. That is intense, and your son is very brave. When I read about your phone call with him, I got a bit teary-eyed.
Writing to heal does a lot to help. I used to write a lot of dark things because it was the anger I had deep within me. But that eventually evolved. The Fan-Fiction I chose to write has a lot of hidden symbolism from a psychological stand-point, regarding my shadow side, my CPTSD, my abuser. Several characters represent different aspects of either me or my mental illness and writing it into a fictional world is symbolic of the internal battles that rage on within me. It's entertaining for me to write it, but it's also been therapeutic in ways I didn't know were possible.
I, too use elements of me in my fictional writings as well. You are right, this lets it out of you in what I believe is a less confrontational way, but healing nonetheless.