KariSue, I'm so, so sorry that you lost Chris. I know how much of a shock it is, especially since he was doing well. My daughter had an accidental overdose in a similar manner and it seemed unreal for a very long time. My heart aches for you.
Please feel free to process all you need to here during this very difficult time. I found it helped me to just pour out my thoughts sometimes, while other times I needed to not think about it. If in time you want some in person grief support, there is an organization called Compassionate Friends, for those who have suffered the loss of a child of any age, that many find very helpful. But we each process our grief in our own way and in our own time, so please know whatever helps you is right for you.
You and your family are in my thoughts.