Welcome..
"Thank You so much!! I am just struggling with do I stay away or should I be here more for him now??"
If your being there would have had a positive impact on him, he would be clean and sober and working a strong recovery program...he is not...it makes no difference if you are with him or not. It is all up to him. he has a disease that has no cure, he will be an addict all his life, it is just a matter of whether he is clean/sober and working a recovery program for life or not...that's it.
Take some time to read the stickeys at the top of this and all the Family & Friends Forums and cynical one's blogs.
Many times alcohol and coke go hand in hand, they get drunk and then do crack/coke, would watch his actions from afar and go from there.