Anger over the death of a child from any circumstance--- illness, accident, suicide, homicide, overdose or unknown--- is justified. However, sometimes it can be hard to recognize and even harder to express. I can say in my own case it has remained like a big dark ball still lingering inside of me.
Anger after the death of a child can be insidious and can mask as depression or overwhelming fatigue. It can also come out in different places, like against other people or in other relationships, social or work situations. Or if it doesn't come out at all, it can eat away at you and affect your physical and emotional health.
In my own case, I would rather not feel my anger so I have been binge eating. I overeat at night to feel pleasure, to feed my anger, rather than express it. Women, especially, have been conditioned by society that it is not acceptable to express anger. It is not unusual for bereaved parents to use alcohol, drugs, gambling or even sex to overcome their sorrow and anger. If this has happened to you, you must get professional counseling to deal with your grief and addiction. This is not something you can do on your own.
I have been receiving grief counseling. As part of that, it has been important to find a way to tap into my anger and express it. I have been taking a racket ball racket and slapping it hard into my bed pillows for about four minutes while thinking about all the things surrounding my son's death that make me angry. Then I listen to a meditation tape to try to clear my mind. Finally I make some notes on what came up to help me process and understand everything.
I know this seems like a lot of work, but the grief process takes effort and the courage to do things you think you can't do. Alternatives may be going for a walk to clear your head or writing down your thoughts.
I am finding out it is important to get to the core of your anger to find some measure of peace with what has happened to your child and to you as a result. This may seem like a very foreign concept to you today as you may still feel too sad or too numb. But it is something that must be worked on eventually for your own well being.