My younger brother was murdered 9 years ago soon after his 22nd birthday. My father died months later. I do not know your pain as a mother, but, boy, I know that loss. I am so sorry.
My mother talked and talked and did whatever she felt like doing. She read and started saying just whatever was on her mind. I don't know if she joined an official support group, but she did get therapy and talked to others. We wish that we had some piece of him to hug and love on and watch grow.
Unfortunately, that hurt does not go away. I still have moments when I can't move because it hurts so much. All I can do is cry and try to release it all from my body. I am tearing up now writing to you. I don't know what you believe spiritually, but try to find some reconciliation and peace in that. Don't be afraid or uncomfortable to feel and express anger. I'll certainly pray for your love and peace, for your shattered heart and soul. I'm sure that you've heard that it gets better over time. Well, it doesn't get better, but it does become part of your reality and it gets less unbearable. I keep up with the anniversary, and it feels so unfair and just wrong that the world has the nerve to keep on turning when all I want is to stop it and catch up. I just want the world to pause for a moment so I can process this blow.
Don't let anyone else dictate your healing. At this point, you don't even want to heal, but I promise that you will be able to smile again, if you want to. It's not the same, but my mother has a son-in-law, now, whom she calls son. She has remarried, and her husband talks about my father like my father is his hero, and he lets her talk about him and cry, etc. My husband noted at their wedding that this was his first time seeing this kind of light in her eyes.
Don't give up. Cry. Curse. Laugh. Scream. Hit (inanimate objects). Kick. Roll up into the fetal position and cry yourself to sleep. Hell, drink wine. Do whatever you need to do to get from moment to moment. It's a moment to moment kind of thing. One day, you'll look around and realize that you've made it a little further. That'll be a big accompolishment, but it'll be so sad, too. You'll know how to respond to it when it happens. Moment to moment.