Your wife will have no idea what she's dealing with if you don't tell her. She must love you very much to put up with your being "emotionally unavailable" to her.
First, tell her you appreciate all that she does, and mean it. Then talk with her. Really talk. Couldn't this clear the air? Please don't just leave and divorce and not give your family a chance.
Perhaps a lot of their happiness is up to you. I remember a quote from Abraham Lincoln, "Most people are about as happy as they make up their minds they want to be."