FirstLight, I'm sorry you are in such pain..No parent should have to face such challenges, but sadly that is why so many of us are here. I think the grieving process is no less painful when a child is lost in addiction. I found the only way to get beyond that incredible pain was to walk through it. I had to do so slowly, in my own time and way; and there were times were I felt stuck...but little by little, I found more peace and acceptance.
I felt very invested physically, financially and emotionally in my daughter's recovery as well and understand that feeling of betrayal. It was only when I shifted the focus to invest the same energy and commitment to my own recovery that I could accept that relapse wasn't done to me; it wasn't personal.
Sometimes the greatest love we can show our children is to let them find their own way. That doesn't make it less painful, but it is a good step towards our own healing.