That's the thing. You can't worry it out or fix it for him, only yourself.
Case in point. My high school sweetheart, teenage marriage, finally came out of the closet and announced he was gay. Big news. I had known it for years, but as we have remained friends, it wasn't my place to make the call. Even if we hadn't remained friends. Anyway, when the AIDS scare was at its heighth, I worried for him. Even though you couldn't say what we had was "love", I still didn't want to see him ill or dying.
Eventually, I learned to accept that his choices held his consequences, and he was a responsible person and, hopefully, would take care of himself. If he didn't, or doesn't, and became ill, I would be there to help him in any way I could. Still will. He is the father of my two oldest children.
But I let go of the self imposed responsiblity of worrying for his health. There is enough going on in our own lives to worry about the careless decisions of other people.
Kissak, take care of YOU, and let God take care of him. You are not responsible for anything he does. It may seem cold hearted, but part of detaching is letting that responsible feeling go.
