First things first. If the cops find these plants in the house, they will take the children away. I know you don't want this to happen. I am also a little unclear about whether you are living in the house with the plants. So, I might be incorrect in assuming you are.
Do you have somewhere you can go? Can you rent an apartment without his knowledge? Can you go to a friends house till the marijuana is GONE?
I reccomend you talk to someone at alanon or naranon. They can find help for you. You really need an OUT. Out of the fear and chaos for at least for one evening. These meetings at alanon will help you tremendously, and you'll meet people who are going through the same thing.
As for the getting him out of your head, well, that takes time and work. We do tend to obsess about people we love. We have to put our self as #1 on the who to take care of list.
I always reccomend getting into something you love to do like yoga, or taking a class that will give you a lift in your life. These things help to take your mind off the addict, at least for the hour you're engaged in the class. And we do need the break
I am sorry you have to feel so scared. I know that feeling well. I have been there too many times.
The nature of an addict, or an alcoholic is always to blame everyone else for everything. What we need to do is recognize their problem is not our fault. Their ugliness and hateful speech is the drug talking. It is NOT your fault and you don't have to feel guilty about anything!
I just want you to know youve come to the right place for support in what you're going through.
Please take good care of yourself. I will say a prayer tonight for you to find peace and well being through all this chaos.