Wow that is a hard one. pray for this dear one of yours and ask God to change his heart and be willing to get help. Tell him you love him too much to sit back and watch him suffer. Tell him you suffer terribly because of watching him suffer. Depending on your relationship to him and whether you are living in the same house, you may have to draw a hard line, kind of like an intervention. I will be praying for your situation. Also, if you are having trouble coping as you said, it would be a very very good idea for you to get help also. A good counselor could help there and perhaps give you some guidance as well as to how to help your loved one.