I am unsure why she on one hand knows that pot has been of benefit to you, but is now saying no or out.

I used to smoke a lot of pot in my teens, and as an adult, I still know people who smoke it -even though I no longer do. I also know someone who used it for MS - perfect for her. But, although I don't think pot is a huge problem, and far less harmful than drink, I do think it does change people. And the bottom line here, as although its not a problem for a lot of folk, smoking pot is causing a problem for you in your marriage.

It sounds to me that she is fixating a few issues onto you smoking pot. Is there a way of trying to talk about it rationally? If not, does she have a problem with medicinal cannabis? Or even baking it? All have the same calming effect. While I do not agree with her threatening to throw you out, sometimes we have to do what we don't want to do for the sake of our marriages if you can't find a compromise.

I hope you guys manage to work something out.