How can I get over this?

First, no doctor told you weed could give you schizophrenia, that's a lie. If you don't want to smoke it, and don't want to be involved with anyone who smokes it, then that's fine, but don't lie about why. Second, you knew a month in that he smoked weed, that's pretty early and plenty of time to decide that you didn't want to be with him, you chose to stay anyway. The big problem is that he wasn't willing to deal with your medical issues, which is part of what you do when you're married. Another problem is that he blames you for the problems in his life, which is crazy and wrong. It shouldn't matter what he wants, do you want a liar who blames you for his issues and won't be there when you need him?