You are so close to the rest of your life. Hang in there. If he needs an event to experience the dark side of the borg, find some recent teaching that he can't accept and ask him to present his ideas to the elder body. For example: new understanding of 'this generation' or the impossibilty of a global flood in 2370BCE. For me, the biggest issue was that I wasn't allowed to disagree with anything. That is not a search for 'truth'.
You need to push him to 'man-up' for your children's sake.