I know it can be maddening when someone close to you, especially a significant other, lives in fantasy land. First of all, you probably feel like there's no one whom you can turn to in order to discuss the constant realization of your deepest fears without being ridiculed as a nutjob.
At a point, you have to come to a decision. This issue isn't just a superficial difference of personality. It's actually THE most important issue in all of our lives. I personally believe that the purpose of a "husband" is to protect and provide for his family. If your spouse is incapable of accepting reality, he is also incapable of fulfilling his role as husband by dealing with the dangers and eventualities that reality will present us. You must ask yourself whether or not you truly want to be married to a sheep who will inevitably lead you into the slaughterhouse.
I'm sorry to be so bleak, and I'm sorry that you are in this unfortunate situation. But please try to remember how serious this is. I've been in the same position as you, and I made the right choice without looking back. Now I'm married to my soulmate. Go figure.
Want DP delivered to your inbox daily? Subscribe here: