I know how hard this is, but I promise you it does get better.
I used to tell my son "I will always love you, no matter what. But I cannot walk through hell with you, so I'll stand in my own recovery and hold the light. Maybe some day you'll follow."
I cope each day by saying a prayer in the morning, asking God to take care of my son, then I live my day well, as life was intended to be lived, and trust God to the rest.
Hugs