Wife is super lazy, wont quit smoking pot, and blames it all on me!?

The issue is not the pot. The issue is her ATTITUDE. She has very little respect for you or the family the two of you have created. And I doubt very much that stopping smoking pot would change that fact. It's simply how she is ... it is how she was in the beginning of the relationship and you were ok with it because you were the same way and there were no children involved. Now you've changed and she has not. This is a common situation, don't feel alone. One partner grows and the other stays the same and the relationship no longer works. You need to leave. And take your child with you. There is no court in the land that would allow her to have sole custody given the details you've provided. Think of it this way : is this the way of life you want to model for your son? I'm sure the answer is no. You know what you need to do.