Married and haven't had sex in almost 2 years! help!

My husband and I have been married 11 years, together 13. We have a 3 year old son that we both adore. My hubby is kind, supportive, and we rarely fight. However, we have not had sex in one year and ten months! He doesn't even touch me in that way. He kisses me like a brother, just a peck on the lips. It makes me feel insecure in our relationship. When I ask him about it, he says he thinks I am sexy, but had zero labido. He is only 40 years old! I love our relationship, but may need to leave him or find some on the side. What would you do if you were in my situation?