What I'm going to say might not be popular or echoed amongst other people in recovery. But, I believe somewhere down the road you will try to stop drinking, in earnest. I'm not sure that this is the time it's going to happen. To me, it would be like asking someone to run for their lives after getting a leg amputated.
You need to get to a place where your son's death is not such an intense pain. At least not as intense as it is now. I lost my oldest son's father, 12 years ago - he was shot and killed right in front of me. So when I describe the pain at first as intense and fresh, I do know from experience that after some time, the pain is still hard to endure, but it becomes more of a dull ache. And this new pain is more easily manageable, and maybe then you can try to remove the dark cloud (alcohol) that - for now - is dulling everything for you.
I wish that you could quit today. But I understand why you may need to wait. And when you're ready, I wish you all the strength in the world to stay sober for the rest of your life. *huge hugs*
Message me whenever you feel the need to.