It seems the details of your story, the feelings that have grown around the situation, and your level of frustration all point to one conclusion: It is time to leave.
It sounds like the thing to do is to plan for your separation. I encourage you to do three things: First, get a legal consult so that you know your rights and the best way to plan. Second, I would begin individual therapy. If you need a therapist, the “find help” tab at the top of the page can help you find one in your area. Finally, I would develop your support network of friends, family, and a divorce support group.
These measures can help you move through this difficult time.
I would also let your husband know that you would like it if the two of you could go for some couples counseling — not so much for reconciliation at this point, but more for helping through this transition.