Oh my......((((((((((((((((anjelmarie))))))))))))))) I'm so sorry. This situation just gets worse and worse. I am kind of at a loss for words because so many things are just wrong with what is going on right now........From what you say here your BF has no real respect or regard for your feelings. Instead he puts his family first. Even when he can see that what he believes is right for his family is literally making you ill. That is a terrible situation to be in. But you already know that

Why is his neice at home all day every day? I don't understand why she never goes out. What does your therapist say? Can s/he help you map out some options? Can s/he help you find ways to be more assertive with your BF? Do you think couples counseling would be an option?? It seems absolutely nuts that your BF is now trying to talk his neice out of moving away, which would be the obvious solution.............

I wish I had something more helpful to say. My heart really, really goes out to you ((((((((((anjelmarie))))))))))) I'm hoping so much that something changes for the better very soon