What should you do if you are in a long term marriage where you are moving in a different direction from your spouse?

I am a 52 year old male, in good shape, active, and looking forward to the next 40 years. My wife is 53, 50 lbs. overweight, and likes to eat candy and clean the house for her hobbies (seriously). We have virtually nothing in common but our two kids. We have no sex life (none). It is like living with your sister. I have been depressed about this for over 10 years. We have tried counseling but nothing changed. How do you get the courage to move on?