As I understand from studies, there are two types of weed smokers.
The Losers - that self harm, do nothing and bum around. Usually jobless and lives off the other half.
If you have this type then dump him.
The Creative - that have a habit that does not overtake their life, but in fact enhances their perception. Usually a very spiritual character. And usually they are good at being successful in work, business and hobbies. You can find many posts online about this.
If you are attracted to this personality type, then stop controlling him. It seems that you have a controlling issue.
These people are usually soft spirited and very nice people.
Does he refrain from responsibility? It sounds like from your posts that he has no other issues. Does he work? Does he provide? What are his aims in life?
Answer these questions first.
I found that the creative types are really successful in life. They have calm but collected manner - usually opposite to the Loser Type.
The Loser Types sleep all day, don't work and are their own worse enemy.
You say 9 years of hell? Why aren't you strong enough to decide before this? Why has it taking so long. It might sound harsh but you don't sound like you are in control of your own life - so project the blame on someone else.
Does he help around the house? Does he restrict you in any way.
Don't get me wrong - but I see the issue seems to be with you and not him. He does not sound like he has changed and if anything has stayed true to himself.
I would recommend that you look within and try to improve yourself and not let your happiness be based on other people.
And I also recommend you both see counselling - this way you both can express freely in a calm environment- you never know but he might find you controlling and as much as you, also would want to resolve any grievances.