Please stay away from this man. Drug use is not an excuse. Take a look at what you are talking about here. Crack and hookers. I am not trying to be harsh, but sometimes we tend to let our own boundary of what is acceptable slide in the sand because it's the drug use. No, it's actually one in the same. Don't compartmentalize this, it is HIS behavior.
You cannot ever fix another person. That is not possible. Find a person who does not need to be fixed before you commit to them!
Hugs.