I agree that your boundaries are personal to you. What you are talking about is a form of coercion--"shape up or x will happen."
Incidentally, lawyers don't (or certainly SHOULDN'T) consult with couples about divorce. You each need your own legal advice--what is good for you isn't necessarily what's good for him. It would be a conflict of interest. What I STRONGLY suggest you do is to consult an attorney yourself and find out what your rights would be in the event of a divorce--whether filed by you or by him. Knowledge is power. You don't have to live in a world of worrying about what-ifs. You don't have to tell him you are doing it (and, in fact, it might be best if you don't).
I haven't heard you say anything good about your marriage or about living with him. So many people think of divorce as some kind of failure, when it can actually be a very positive and empowering act. Regaining a sense of control over your OWN destiny instead of being at the mercy of someone else's moods and whims can life-changing. I suggest you start reframing the idea in your head as a gateway to freedom rather than contemplating it as something to fear.