Oh (((Hurt)))
I know first hand the feelings you are experiencing.
My son is 24 also, and currently continues to stay in his addiction. He's made some improvements, but not solid decisions...yet. I still have hope.
A few things I want to mention (none of which will solve anything)
I've had to come to the painful realization that he does what he does because he's an addict. I first thought acceptance was admittance, but after time learned that I had to accept addictive behaviors and not let it blind-side me when he did things that addicts do (like relapse, make poor decisions, lie etc) It doesn't paint a prettier picture, but it does allow me to not get my expectations too high, which will often lead to disappointment.
I also have learned that I am not alone, and either are you. I'm from the same area as you and each year, unfortunately, I hear of another victim of addiction. Many of the people I feared would learn "our secret" are now experiencing the same pain as you and I. Its not a moral or character defect, its a disease and its reached epidemic proportions with our young adults. When they will choose to manage this disease no one knows, but I do in my heart believe they can.
And last but not least, you are not responsible for him, his decisions (good or bad) or for helping others to come to grips with the reality of addiction. We have enough on our plate trying to understand ourselves.
I will be thinking of you and your family
(((Hugs)))