You've known each other for a long long time. Both of you have issues. A part of me believes that we find and marry people, in order to resolve the issues that come up during the relationship.
His use of drugs is unacceptable, as is his "avoidance" of stress. All of us need to learn how to face ourselves, face stress, and learn how to forgive others and ourselves.
Can you forgive him? Can you forgive yourself for getting into your current situation. I know how helpless one can feel with an uncooperative partner, someone who won't work on him/herself.
Why does he use drugs? That might be an incredibly difficult issue for him to face. Is he manipulating his environment due to lack of love in his past? Is he filling a hole?
Interestingly, I wonder what heavy metal detoxification or parasite cleanses or ozone therapy or fasting might do in your situation. Unfortunately, to go in the direction of true health, we need to find doctors who are "few and far between," or, we need to forge our own path.
I see the drug issue as a symptom of a larger health issue, which is the result of spiritual, emotional, and mental trauma, patterns, problems, decisions, and many things that aren't your fault at all...but they've become your responsibility.
I sense that you are a very strong and capable person. That people rely on you, because you are reliable.
I believe that if you breathe and breathe deeply, and if you take just a few moments a day to really breathe and pray, that you will know what you need to do.
Peace,
D--